diff --git a/features/alignment-baseline.yml.dist b/features/alignment-baseline.yml.dist
index b4566d25001..9daac062e3b 100644
--- a/features/alignment-baseline.yml.dist
+++ b/features/alignment-baseline.yml.dist
@@ -10,12 +10,31 @@ status:
     safari: "5.1"
     safari_ios: "5"
 compat_features:
+  # baseline: low
+  # baseline_low_date: 2026-03-24
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "79"
+  #   firefox: "149"
+  #   firefox_android: "149"
+  #   safari: "5.1"
+  #   safari_ios: "5"
   - css.properties.alignment-baseline
-  - css.properties.alignment-baseline.alphabetic
   - css.properties.alignment-baseline.baseline
+  - css.properties.alignment-baseline.middle
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: false
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "79"
+  #   safari: "5.1"
+  #   safari_ios: "5"
+  - css.properties.alignment-baseline.alphabetic
   - css.properties.alignment-baseline.central
   - css.properties.alignment-baseline.ideographic
   - css.properties.alignment-baseline.mathematical
-  - css.properties.alignment-baseline.middle
   - css.properties.alignment-baseline.text-after-edge
   - css.properties.alignment-baseline.text-before-edge
diff --git a/features/async-iterable-streams.yml.dist b/features/async-iterable-streams.yml.dist
index 6ab9480b151..04c7c2ef317 100644
--- a/features/async-iterable-streams.yml.dist
+++ b/features/async-iterable-streams.yml.dist
@@ -10,5 +10,24 @@ status:
     firefox: "110"
     firefox_android: "110"
 compat_features:
+  # baseline: low
+  # baseline_low_date: 2026-03-24
+  # support:
+  #   chrome: "124"
+  #   chrome_android: "124"
+  #   edge: "124"
+  #   firefox: "110"
+  #   firefox_android: "110"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.ReadableStream.@@asyncIterator
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: false
+  # support:
+  #   chrome: "124"
+  #   chrome_android: "124"
+  #   edge: "124"
+  #   firefox: "110"
+  #   firefox_android: "110"
   - api.ReadableStream.values
diff --git a/features/baseline-shift.yml.dist b/features/baseline-shift.yml.dist
index fab29086ad9..09512231e9e 100644
--- a/features/baseline-shift.yml.dist
+++ b/features/baseline-shift.yml.dist
@@ -10,7 +10,26 @@ status:
     safari: "4"
     safari_ios: "3.2"
 compat_features:
+  # baseline: low
+  # baseline_low_date: 2026-03-24
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "79"
+  #   firefox: "149"
+  #   firefox_android: "149"
+  #   safari: "4"
+  #   safari_ios: "3.2"
   - css.properties.baseline-shift
-  - css.properties.baseline-shift.baseline
   - css.properties.baseline-shift.sub
   - css.properties.baseline-shift.super
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: false
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "79"
+  #   safari: "4"
+  #   safari_ios: "3.2"
+  - css.properties.baseline-shift.baseline
diff --git a/features/capture-stream-audio-video.yml.dist b/features/capture-stream-audio-video.yml.dist
index 074bc5dd035..233192fd8b0 100644
--- a/features/capture-stream-audio-video.yml.dist
+++ b/features/capture-stream-audio-video.yml.dist
@@ -7,5 +7,7 @@ status:
     chrome: "62"
     chrome_android: "62"
     edge: "79"
+    firefox: "149"
+    firefox_android: "149"
 compat_features:
   - api.HTMLMediaElement.captureStream
diff --git a/features/clear-site-data.yml.dist b/features/clear-site-data.yml.dist
index 8916ea314d0..ef16f139ff7 100644
--- a/features/clear-site-data.yml.dist
+++ b/features/clear-site-data.yml.dist
@@ -18,25 +18,16 @@ compat_features:
   - http.headers.Clear-Site-Data.secure_context_required
   - http.headers.Clear-Site-Data.storage
 
-  # baseline: high
-  # baseline_low_date: 2023-09-18
-  # baseline_high_date: 2026-03-18
+  # baseline: false
   # support:
-  #   chrome: "117"
-  #   chrome_android: "117"
-  #   edge: "117"
   #   firefox: "63"
   #   firefox_android: "63"
   #   safari: "17"
   #   safari_ios: "17"
   - http.headers.Clear-Site-Data.wildcard
 
-  # baseline: low
-  # baseline_low_date: 2025-04-29
+  # baseline: false
   # support:
-  #   chrome: "65"
-  #   chrome_android: "65"
-  #   edge: "79"
   #   firefox: "138"
   #   firefox_android: "138"
   #   safari: "17"
diff --git a/features/closewatcher.yml.dist b/features/closewatcher.yml.dist
index 731c38f0cf6..5071e74395b 100644
--- a/features/closewatcher.yml.dist
+++ b/features/closewatcher.yml.dist
@@ -7,6 +7,8 @@ status:
     chrome: "126"
     chrome_android: "126"
     edge: "126"
+    firefox: "149"
+    firefox_android: "149"
 compat_features:
   - api.CloseWatcher
   - api.CloseWatcher.CloseWatcher
diff --git a/features/createimagebitmap.yml.dist b/features/createimagebitmap.yml.dist
index 4b4f7304173..913e3c4d4f1 100644
--- a/features/createimagebitmap.yml.dist
+++ b/features/createimagebitmap.yml.dist
@@ -120,11 +120,14 @@ compat_features:
   #   safari_ios: "17.2"
   - api.createImageBitmap.svgimageelement_as_source_image
 
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "54"
   #   chrome_android: "54"
   #   edge: "79"
+  #   firefox: "149"
+  #   firefox_android: "149"
   #   safari: "15"
   #   safari_ios: "15"
   - api.createImageBitmap.options_resizeQuality_parameter
diff --git a/features/csp.yml.dist b/features/csp.yml.dist
index c65ce4acd60..c576dd87fd3 100644
--- a/features/csp.yml.dist
+++ b/features/csp.yml.dist
@@ -363,6 +363,18 @@ compat_features:
   #   safari_ios: "26.2"
   - http.headers.Content-Security-Policy.style-src-elem
 
+  # baseline: low
+  # baseline_low_date: 2026-03-24
+  # support:
+  #   chrome: "70"
+  #   chrome_android: "70"
+  #   edge: "79"
+  #   firefox: "149"
+  #   firefox_android: "149"
+  #   safari: "16.4"
+  #   safari_ios: "16.4"
+  - http.headers.Content-Security-Policy.report-to
+
   # baseline: false
   # support:
   #   chrome: "56"
@@ -372,15 +384,6 @@ compat_features:
   #   firefox_android: "63"
   - api.SecurityPolicyViolationEvent.worker_support
 
-  # baseline: false
-  # support:
-  #   chrome: "70"
-  #   chrome_android: "70"
-  #   edge: "79"
-  #   safari: "16.4"
-  #   safari_ios: "16.4"
-  - http.headers.Content-Security-Policy.report-to
-
   # baseline: false
   # support:
   #   chrome: "61"
diff --git a/features/dom.yml.dist b/features/dom.yml.dist
index ad98db9a560..aae81712bc3 100644
--- a/features/dom.yml.dist
+++ b/features/dom.yml.dist
@@ -1293,21 +1293,27 @@ compat_features:
   #   safari_ios: "1"
   - api.HTMLElement.outerText
 
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2025-09-15
   # support:
   #   chrome: "56"
   #   chrome_android: "56"
   #   edge: "79"
   #   firefox: "50"
   #   firefox_android: "50"
+  #   safari: "26"
+  #   safari_ios: "26"
   - api.Document.createElement.options_parameter
   - api.Document.createElementNS.options_parameter
 
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "128"
   #   chrome_android: "128"
   #   edge: "128"
   #   firefox: "126"
   #   firefox_android: "126"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.Element.currentCSSZoom
diff --git a/features/draft/spec/css-grid-3.yml.dist b/features/draft/spec/css-grid-3.yml.dist
index e044ce71c63..36297fb51ef 100644
--- a/features/draft/spec/css-grid-3.yml.dist
+++ b/features/draft/spec/css-grid-3.yml.dist
@@ -3,7 +3,9 @@
 
 status:
   baseline: false
-  support: {}
+  support:
+    safari: "26.4"
+    safari_ios: "26.4"
 compat_features:
   # baseline: high
   # baseline_low_date: 2017-10-17
@@ -57,7 +59,9 @@ compat_features:
 
   # ⬇️ Same status as overall feature ⬇️
   # baseline: false
-  # support: {}
+  # support:
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - css.properties.display.grid-lanes
   - css.properties.display.inline-grid-lanes
   - css.properties.flow-tolerance
diff --git a/features/draft/spec/css-inline-3.yml.dist b/features/draft/spec/css-inline-3.yml.dist
index fa1334da0c2..b29fd80c271 100644
--- a/features/draft/spec/css-inline-3.yml.dist
+++ b/features/draft/spec/css-inline-3.yml.dist
@@ -33,9 +33,10 @@ compat_features:
   - css.properties.text-box.ideographic
   - css.properties.text-box.ideographic-ink
 
-  # ⬇️ Same status as overall feature ⬇️
   # baseline: false
-  # support: {}
+  # support:
+  #   firefox: "149"
+  #   firefox_android: "149"
   - css.properties.alignment-baseline.text-bottom
   - css.properties.alignment-baseline.text-top
   - css.properties.baseline-shift.bottom
diff --git a/features/draft/spec/html.yml.dist b/features/draft/spec/html.yml.dist
index 7bea701d590..30a99caad0e 100644
--- a/features/draft/spec/html.yml.dist
+++ b/features/draft/spec/html.yml.dist
@@ -913,6 +913,14 @@ compat_features:
   - api.HTMLInputElement.showPicker.month_input
   - api.HTMLInputElement.showPicker.week_input
 
+  # baseline: false
+  # support:
+  #   chrome: "99"
+  #   chrome_android: "99"
+  #   edge: "99"
+  #   firefox: "149"
+  - api.HTMLInputElement.showPicker.datalist_input
+
   # baseline: false
   # support:
   #   firefox: "127"
@@ -958,7 +966,6 @@ compat_features:
   #   chrome_android: "99"
   #   edge: "99"
   - api.HTMLInputElement.showPicker.autocomplete_input
-  - api.HTMLInputElement.showPicker.datalist_input
 
   # baseline: false
   # support:
diff --git a/features/draft/spec/mathml-core.yml.dist b/features/draft/spec/mathml-core.yml.dist
index b5d0dc7db51..dd1f2a5d5cb 100644
--- a/features/draft/spec/mathml-core.yml.dist
+++ b/features/draft/spec/mathml-core.yml.dist
@@ -2,13 +2,16 @@
 # Do not edit this file by hand. Edit the source file instead!
 
 status:
-  baseline: false
+  baseline: low
+  baseline_low_date: 2026-03-24
   support:
     chrome: "109"
     chrome_android: "109"
     edge: "109"
     firefox: "146"
     firefox_android: "146"
+    safari: "26.4"
+    safari_ios: "26.4"
 compat_features:
   # baseline: high
   # baseline_low_date: 2023-08-29
@@ -37,11 +40,14 @@ compat_features:
   - css.properties.math-shift.compact
   - css.properties.math-shift.normal
 
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "109"
   #   chrome_android: "109"
   #   edge: "109"
   #   firefox: "117"
   #   firefox_android: "117"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - css.properties.math-depth.auto-add
diff --git a/features/draft/spec/resource-timing.yml.dist b/features/draft/spec/resource-timing.yml.dist
index f1f45d616e4..3d7c218f118 100644
--- a/features/draft/spec/resource-timing.yml.dist
+++ b/features/draft/spec/resource-timing.yml.dist
@@ -13,6 +13,8 @@ compat_features:
   #   chrome: "133"
   #   chrome_android: "133"
   #   edge: "133"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.PerformanceResourceTiming.finalResponseHeadersStart
 
   # baseline: false
diff --git a/features/draft/spec/webdriver-bidi.yml.dist b/features/draft/spec/webdriver-bidi.yml.dist
index 23356e3567d..b4e7d268fa0 100644
--- a/features/draft/spec/webdriver-bidi.yml.dist
+++ b/features/draft/spec/webdriver-bidi.yml.dist
@@ -604,6 +604,17 @@ compat_features:
   #   firefox_android: "146"
   - webdriver.bidi.network.getData.dataType_parameter.request
 
+  # baseline: false
+  # support:
+  #   chrome: "142"
+  #   chrome_android: "142"
+  #   edge: "142"
+  #   firefox: "149"
+  #   firefox_android: "149"
+  - webdriver.bidi.browser.setDownloadBehavior
+  - webdriver.bidi.browser.setDownloadBehavior.downloadBehavior_parameter
+  - webdriver.bidi.browser.setDownloadBehavior.userContexts_parameter
+
   # baseline: false
   # support:
   #   chrome: "126"
@@ -695,15 +706,6 @@ compat_features:
   - webdriver.bidi.emulation.setScriptingEnabled.enabled_parameter
   - webdriver.bidi.emulation.setScriptingEnabled.userContexts_parameter
 
-  # baseline: false
-  # support:
-  #   chrome: "142"
-  #   chrome_android: "142"
-  #   edge: "142"
-  - webdriver.bidi.browser.setDownloadBehavior
-  - webdriver.bidi.browser.setDownloadBehavior.downloadBehavior_parameter
-  - webdriver.bidi.browser.setDownloadBehavior.userContexts_parameter
-
   # baseline: false
   # support:
   #   chrome: "143"
diff --git a/features/draft/spec/webtransport.yml.dist b/features/draft/spec/webtransport.yml.dist
index 345677d4df8..10452550b93 100644
--- a/features/draft/spec/webtransport.yml.dist
+++ b/features/draft/spec/webtransport.yml.dist
@@ -3,18 +3,24 @@
 
 status:
   baseline: false
-  support: {}
+  support:
+    safari: "26.4"
+    safari_ios: "26.4"
 compat_features:
   # baseline: false
   # support:
   #   chrome: "143"
   #   chrome_android: "143"
   #   edge: "143"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.protocol
 
   # ⬇️ Same status as overall feature ⬇️
   # baseline: false
-  # support: {}
+  # support:
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.anticipatedConcurrentIncomingBidirectionalStreams
   - api.WebTransport.anticipatedConcurrentIncomingUnidirectionalStreams
   - api.WebTransport.createSendGroup
diff --git a/features/fetch.yml.dist b/features/fetch.yml.dist
index 1da273113dd..5c4cb2793f8 100644
--- a/features/fetch.yml.dist
+++ b/features/fetch.yml.dist
@@ -366,6 +366,18 @@ compat_features:
   - api.Request.bytes
   - api.Response.bytes
 
+  # baseline: low
+  # baseline_low_date: 2026-03-24
+  # support:
+  #   chrome: "116"
+  #   chrome_android: "116"
+  #   edge: "116"
+  #   firefox: "102"
+  #   firefox_android: "102"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
+  - api.Response.body.readable_byte_stream
+
   # baseline: false
   # support:
   #   chrome: "43"
@@ -406,15 +418,6 @@ compat_features:
   #   safari_ios: "10.3"
   - api.Request.cache.only-if-cached
 
-  # baseline: false
-  # support:
-  #   chrome: "116"
-  #   chrome_android: "116"
-  #   edge: "116"
-  #   firefox: "102"
-  #   firefox_android: "102"
-  - api.Response.body.readable_byte_stream
-
   # baseline: false
   # support:
   #   firefox: "111"
diff --git a/features/font-family-math.yml.dist b/features/font-family-math.yml.dist
index 9b084b1e99e..101833647a4 100644
--- a/features/font-family-math.yml.dist
+++ b/features/font-family-math.yml.dist
@@ -2,11 +2,14 @@
 # Do not edit this file by hand. Edit the source file instead!
 
 status:
-  baseline: false
+  baseline: low
+  baseline_low_date: 2026-03-24
   support:
     chrome: "109"
     chrome_android: "109"
     edge: "109"
+    firefox: "149"
+    firefox_android: "149"
     safari: "26.2"
     safari_ios: "26.2"
 compat_features:
diff --git a/features/history.yml.dist b/features/history.yml.dist
index 8ae6ed14d87..a800ae22b65 100644
--- a/features/history.yml.dist
+++ b/features/history.yml.dist
@@ -113,11 +113,14 @@ compat_features:
   #   safari_ios: "11"
   - api.History.scrollRestoration
 
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "118"
   #   chrome_android: "118"
   #   edge: "118"
+  #   firefox: "149"
+  #   firefox_android: "149"
   #   safari: "18"
   #   safari_ios: "18"
   - api.PopStateEvent.hasUAVisualTransition
diff --git a/features/input-color-alpha.yml.dist b/features/input-color-alpha.yml.dist
index cf67cdd8849..190fed66bb5 100644
--- a/features/input-color-alpha.yml.dist
+++ b/features/input-color-alpha.yml.dist
@@ -7,7 +7,19 @@ status:
     safari: "18.4"
     safari_ios: "18.4"
 compat_features:
-  - api.HTMLInputElement.alpha
+  # baseline: false
+  # support:
+  #   firefox: "149"
+  #   firefox_android: "149"
+  #   safari: "18.4"
+  #   safari_ios: "18.4"
   - api.HTMLInputElement.colorSpace
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: false
+  # support:
+  #   safari: "18.4"
+  #   safari_ios: "18.4"
+  - api.HTMLInputElement.alpha
   - html.elements.input.alpha
   - html.elements.input.colorspace
diff --git a/features/iterator-concat.yml.dist b/features/iterator-concat.yml.dist
index 27c2b923e10..b568958b179 100644
--- a/features/iterator-concat.yml.dist
+++ b/features/iterator-concat.yml.dist
@@ -2,12 +2,15 @@
 # Do not edit this file by hand. Edit the source file instead!
 
 status:
-  baseline: false
+  baseline: low
+  baseline_low_date: 2026-03-24
   support:
     chrome: "146"
     chrome_android: "146"
     edge: "146"
     firefox: "147"
     firefox_android: "147"
+    safari: "26.4"
+    safari_ios: "26.4"
 compat_features:
   - javascript.builtins.Iterator.concat
diff --git a/features/loading-lazy-media.yml.dist b/features/loading-lazy-media.yml.dist
index 66f3fe0ed07..0774f6da1d8 100644
--- a/features/loading-lazy-media.yml.dist
+++ b/features/loading-lazy-media.yml.dist
@@ -4,3 +4,7 @@
 status:
   baseline: false
   support: {}
+compat_features:
+  - api.HTMLMediaElement.loading
+  - html.elements.audio.loading
+  - html.elements.video.autoplay.loading
diff --git a/features/mathml.yml.dist b/features/mathml.yml.dist
index 1e94a8e0e6a..e496205345a 100644
--- a/features/mathml.yml.dist
+++ b/features/mathml.yml.dist
@@ -282,6 +282,19 @@ compat_features:
   #   safari_ios: "26.2"
   - css.properties.math-shift
 
+  # baseline: low
+  # baseline_low_date: 2026-03-24
+  # support:
+  #   chrome: "109"
+  #   chrome_android: "109"
+  #   edge: "109"
+  #   firefox: "117"
+  #   firefox_android: "117"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
+  - css.properties.font-size.math
+  - css.properties.math-depth
+
   # baseline: false
   # support:
   #   chrome: "109"
@@ -316,8 +329,6 @@ compat_features:
   #   edge: "109"
   #   firefox: "117"
   #   firefox_android: "117"
-  - css.properties.font-size.math
-  - css.properties.math-depth
   - css.properties.text-transform.math-auto
 
   # baseline: false
diff --git a/features/overflow-clip-margin.yml.dist b/features/overflow-clip-margin.yml.dist
index f2c2bf10541..45cfde0fefc 100644
--- a/features/overflow-clip-margin.yml.dist
+++ b/features/overflow-clip-margin.yml.dist
@@ -3,9 +3,21 @@
 
 status:
   baseline: false
-  support: {}
+  support:
+    firefox: "148"
+    firefox_android: "148"
 compat_features:
+  # baseline: false
+  # support:
+  #   firefox: "102"
+  #   firefox_android: "102"
   - css.properties.overflow-clip-margin
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: false
+  # support:
+  #   firefox: "148"
+  #   firefox_android: "148"
   - css.properties.overflow-clip-margin.border-box
   - css.properties.overflow-clip-margin.content-box
   - css.properties.overflow-clip-margin.padding-box
diff --git a/features/popover-hint.yml.dist b/features/popover-hint.yml.dist
index 00300eb69e9..dfca61a5529 100644
--- a/features/popover-hint.yml.dist
+++ b/features/popover-hint.yml.dist
@@ -7,6 +7,8 @@ status:
     chrome: "133"
     chrome_android: "133"
     edge: "133"
+    firefox: "149"
+    firefox_android: "149"
 compat_features:
   - api.HTMLElement.popover.hint
   - html.global_attributes.popover.hint
diff --git a/features/readable-byte-streams.yml.dist b/features/readable-byte-streams.yml.dist
index e8814465fa4..388ca22e079 100644
--- a/features/readable-byte-streams.yml.dist
+++ b/features/readable-byte-streams.yml.dist
@@ -2,22 +2,28 @@
 # Do not edit this file by hand. Edit the source file instead!
 
 status:
-  baseline: false
+  baseline: low
+  baseline_low_date: 2026-03-24
   support:
     chrome: "89"
     chrome_android: "89"
     edge: "89"
     firefox: "102"
     firefox_android: "102"
+    safari: "26.4"
+    safari_ios: "26.4"
 compat_features:
   # ⬇️ Same status as overall feature ⬇️
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "89"
   #   chrome_android: "89"
   #   edge: "89"
   #   firefox: "102"
   #   firefox_android: "102"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.ReadableByteStreamController
   - api.ReadableByteStreamController.byobRequest
   - api.ReadableByteStreamController.close
diff --git a/features/reporting.yml.dist b/features/reporting.yml.dist
index bd7802a7af2..fad2e81bc2a 100644
--- a/features/reporting.yml.dist
+++ b/features/reporting.yml.dist
@@ -2,19 +2,25 @@
 # Do not edit this file by hand. Edit the source file instead!
 
 status:
-  baseline: false
+  baseline: low
+  baseline_low_date: 2026-03-24
   support:
     chrome: "96"
     chrome_android: "96"
     edge: "96"
+    firefox: "149"
+    firefox_android: "149"
     safari: "16.4"
     safari_ios: "16.4"
 compat_features:
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "69"
   #   chrome_android: "69"
   #   edge: "79"
+  #   firefox: "149"
+  #   firefox_android: "149"
   #   safari: "16.4"
   #   safari_ios: "16.4"
   - api.ReportingObserver
@@ -25,39 +31,38 @@ compat_features:
   - api.ReportingObserver.observe
   - api.ReportingObserver.takeRecords
 
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "74"
   #   chrome_android: "74"
   #   edge: "79"
+  #   firefox: "149"
+  #   firefox_android: "149"
   #   safari: "18.4"
   #   safari_ios: "18.4"
   - api.ReportingObserver.ReportingObserver.options_parameter.types_property.csp-violation
 
   # ⬇️ Same status as overall feature ⬇️
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "96"
   #   chrome_android: "96"
   #   edge: "96"
+  #   firefox: "149"
+  #   firefox_android: "149"
   #   safari: "16.4"
   #   safari_ios: "16.4"
   - http.headers.Reporting-Endpoints
 
-  # baseline: false
-  # support:
-  #   chrome: "69"
-  #   chrome_android: "69"
-  #   edge: "79"
-  - api.ReportingObserver.ReportingObserver.options_parameter.types_property.coep
-  - api.ReportingObserver.ReportingObserver.options_parameter.types_property.deprecation
-  - api.ReportingObserver.ReportingObserver.options_parameter.types_property.intervention
-
   # baseline: false
   # support:
   #   chrome: "84"
   #   chrome_android: "84"
   #   edge: "84"
+  #   firefox: "149"
+  #   firefox_android: "149"
   - api.ReportingObserver.worker_support
 
   # baseline: false
@@ -65,4 +70,15 @@ compat_features:
   #   chrome: "138"
   #   chrome_android: "138"
   #   edge: "138"
+  #   firefox: "149"
+  #   firefox_android: "149"
   - api.ReportingObserver.ReportingObserver.options_parameter.types_property.integrity-violation
+
+  # baseline: false
+  # support:
+  #   chrome: "69"
+  #   chrome_android: "69"
+  #   edge: "79"
+  - api.ReportingObserver.ReportingObserver.options_parameter.types_property.coep
+  - api.ReportingObserver.ReportingObserver.options_parameter.types_property.deprecation
+  - api.ReportingObserver.ReportingObserver.options_parameter.types_property.intervention
diff --git a/features/resource-timing.yml.dist b/features/resource-timing.yml.dist
index ebe0550b965..384a9f62c2c 100644
--- a/features/resource-timing.yml.dist
+++ b/features/resource-timing.yml.dist
@@ -149,18 +149,13 @@ compat_features:
   #   firefox_android: "129"
   - api.PerformanceResourceTiming.responseStatus
 
-  # baseline: false
-  # support:
-  #   chrome: "107"
-  #   chrome_android: "107"
-  #   edge: "107"
-  - api.PerformanceResourceTiming.renderBlockingStatus
-
   # baseline: false
   # support:
   #   chrome: "115"
   #   chrome_android: "115"
   #   edge: "115"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.PerformanceResourceTiming.firstInterimResponseStart
 
   # baseline: false
@@ -168,8 +163,17 @@ compat_features:
   #   chrome: "117"
   #   chrome_android: "117"
   #   edge: "117"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.PerformanceResourceTiming.deliveryType
 
+  # baseline: false
+  # support:
+  #   chrome: "107"
+  #   chrome_android: "107"
+  #   edge: "107"
+  - api.PerformanceResourceTiming.renderBlockingStatus
+
   # baseline: false
   # support:
   #   firefox: "129"
diff --git a/features/webtransport.yml.dist b/features/webtransport.yml.dist
index 37ca461f97a..d996c3fe43e 100644
--- a/features/webtransport.yml.dist
+++ b/features/webtransport.yml.dist
@@ -2,22 +2,28 @@
 # Do not edit this file by hand. Edit the source file instead!
 
 status:
-  baseline: false
+  baseline: low
+  baseline_low_date: 2026-03-24
   support:
     chrome: "97"
     chrome_android: "97"
     edge: "97"
     firefox: "114"
     firefox_android: "114"
+    safari: "26.4"
+    safari_ios: "26.4"
 compat_features:
   # ⬇️ Same status as overall feature ⬇️
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "97"
   #   chrome_android: "97"
   #   edge: "97"
   #   firefox: "114"
   #   firefox_android: "114"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport
   - api.WebTransport.WebTransport
   - api.WebTransport.close
@@ -42,22 +48,28 @@ compat_features:
   - api.WebTransportError.source
   - api.WebTransportError.streamErrorCode
 
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "100"
   #   chrome_android: "100"
   #   edge: "100"
   #   firefox: "125"
   #   firefox_android: "125"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.WebTransport.options_serverCertificateHashes_parameter
 
-  # baseline: false
+  # baseline: low
+  # baseline_low_date: 2026-03-24
   # support:
   #   chrome: "109"
   #   chrome_android: "109"
   #   edge: "109"
   #   firefox: "114"
   #   firefox_android: "114"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.byob_readers
 
   # baseline: false
@@ -65,6 +77,8 @@ compat_features:
   #   chrome: "97"
   #   chrome_android: "97"
   #   edge: "97"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.createUnidirectionalStream
 
   # baseline: false
@@ -72,6 +86,8 @@ compat_features:
   #   chrome: "109"
   #   chrome_android: "109"
   #   edge: "109"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.createUnidirectionalStream.byob_readers
   - api.WebTransportDatagramDuplexStream.byob_readers
 
@@ -79,6 +95,8 @@ compat_features:
   # support:
   #   firefox: "114"
   #   firefox_android: "114"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.WebTransport.options_allowPooling_parameter
   - api.WebTransport.WebTransport.options_congestionControl_parameter
   - api.WebTransport.WebTransport.options_requireUnreliable_parameter
@@ -96,15 +114,21 @@ compat_features:
   # support:
   #   firefox: "119"
   #   firefox_android: "119"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.createBidirectionalStream.options_sendOrder_parameter
 
   # baseline: false
   # support:
   #   firefox: "121"
   #   firefox_android: "121"
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransportSendStream.sendOrder
 
   # baseline: false
-  # support: {}
+  # support:
+  #   safari: "26.4"
+  #   safari_ios: "26.4"
   - api.WebTransport.createUnidirectionalStream.options_sendOrder_parameter
   - api.WebTransport.getStats
diff --git a/package-lock.json b/package-lock.json
index 8ae7459a6f7..3f15a4d0c8e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,7 +13,7 @@
       "devDependencies": {
         "@eslint/js": "^10.0.1",
         "@js-temporal/polyfill": "^0.5.1",
-        "@mdn/browser-compat-data": "7.3.8",
+        "@mdn/browser-compat-data": "7.3.9",
         "@octokit/rest": "^22.0.1",
         "@types/caniuse-lite": "^1.0.4",
         "@types/node": "^20.19.37",
@@ -1025,9 +1025,9 @@
       }
     },
     "node_modules/@mdn/browser-compat-data": {
-      "version": "7.3.8",
-      "resolved": "https://registry.npmjs.org/@mdn/browser-compat-data/-/browser-compat-data-7.3.8.tgz",
-      "integrity": "sha512-NxKcWM1ydMiJC2fvox3TpWstn5LmkM1wQ6Maw1BVqsVvmFR80TD4GVXT/qBRCGDhpNSxanuJp25DYkdAXJrFJQ==",
+      "version": "7.3.9",
+      "resolved": "https://registry.npmjs.org/@mdn/browser-compat-data/-/browser-compat-data-7.3.9.tgz",
+      "integrity": "sha512-ARxwDFfq4uhRSd9Wr1FMaxeKKIFDPyMnSoLe/8WX+nNXbKDILf1H8KDJW9nzu2QTR0hQ37jDCzAgyaNYdLzACQ==",
       "license": "CC0-1.0"
     },
     "node_modules/@octokit/auth-token": {
diff --git a/package.json b/package.json
index f275ffa90fb..c0790682f7c 100644
--- a/package.json
+++ b/package.json
@@ -40,7 +40,7 @@
   "devDependencies": {
     "@eslint/js": "^10.0.1",
     "@js-temporal/polyfill": "^0.5.1",
-    "@mdn/browser-compat-data": "7.3.8",
+    "@mdn/browser-compat-data": "7.3.9",
     "@octokit/rest": "^22.0.1",
     "@types/caniuse-lite": "^1.0.4",
     "@types/node": "^20.19.37",