diff --git a/src/neuron_proofreader/merge_proofreading/merge_datamodules.py b/src/neuron_proofreader/merge_proofreading/merge_datamodules.py
index d9b336a..4687409 100644
--- a/src/neuron_proofreader/merge_proofreading/merge_datamodules.py
+++ b/src/neuron_proofreader/merge_proofreading/merge_datamodules.py
@@ -63,7 +63,7 @@ class BrainDataset:
     """
 
     giant_component_cable_length = 30000
-    random_branching_site_probability = 0.5
+    random_branching_site_probability = 0.25
 
     def __init__(
         self,
@@ -171,13 +171,13 @@ def get_random_nonmerge_site(self):
             # Sample node
             node = util.sample_once(nodes)
             if self.is_valid_nonmerge_site(node):
-                return node
+                return node, 0
 
             # Try again
             n_attempts += 1
             if n_attempts > 100:
                 print(f"Failed to find valid random nonmerge site for {self.brain_id}!")
-                return util.sample_once(self.nodes)
+                return util.sample_once(self.nodes), 0
 
     # --- Helpers ---
     def add_nonmerge_sites(self, num_sites):
@@ -228,7 +228,7 @@ def _has_nearby_branching(self, root, max_depth=100):
         while queue:
             # Visit node
             i, d_i = queue.pop()
-            if self.degree[i] > 2 and d_i > 0:
+            if self.degree[i] >= 3 and i != root:
                 return True
 
             # Update queue
@@ -608,6 +608,7 @@ def create_dataset_collection(
     graph_config=None,
     img_config=None,
     subgraph_depth=100,
+    val_neg_multiplier=5,
 ):
     # Set parameters based on mode
     print(f"\nLoading {dataset_mode} Dataset...")
@@ -654,7 +655,7 @@ def create_dataset_collection(
 
         # Check whether to generate examples for validation
         if dataset_mode == "Val":
-            num_target_neg = 5 * len(dataset.merge_sites)
+            num_target_neg = val_neg_multiplier * len(dataset.merge_sites)
             num_added_neg = num_target_neg - len(dataset.nonmerge_sites)
             dataset.add_nonmerge_sites(num_added_neg)
 
diff --git a/src/neuron_proofreader/utils/swc_util.py b/src/neuron_proofreader/utils/swc_util.py
index 00e828f..3be81da 100644
--- a/src/neuron_proofreader/utils/swc_util.py
+++ b/src/neuron_proofreader/utils/swc_util.py
@@ -159,7 +159,7 @@ def read_swcs(self, swc_paths):
         Parameters
         ----------
         swc_paths : List[str]
-            List of paths to SWC files to be read.
+            Paths to SWC files to be read.
 
         Returns
         -------
@@ -448,14 +448,13 @@ def parse(self, content, filename):
 
     def process_content(self, content):
         """
-        Processes lines of text from an SWC file, extracting an offset
-        value and returning the remaining content starting from the line
-        immediately after the last commented line.
+        Extracts an offset and returns the remaining content starting from the
+        line after the last commented line.
 
         Parameters
         ----------
         content : List[str]
-            List of strings such that each is a line from an SWC file.
+            Lines from an SWC file.
 
         Returns
         -------
@@ -475,7 +474,7 @@ def process_content(self, content):
 
     def read_coordinate(self, xyz_str, offset=(0, 0, 0)):
         """
-        Reads a coordinate from a string and converts it to voxel coordinates.
+        Reads coordinate from a string and converts it to voxel coordinates.
 
         Parameters
         ----------
@@ -498,7 +497,7 @@ def write_points(
     zip_path, points, color=None, prefix="", radius=10, write_mode="w"
 ):
     """
-    Writes a list of 3D points to individual SWC files in the specified
+    Writes list of 3D points to individual SWC files in the specified
     directory.
 
     Parameters
@@ -524,15 +523,14 @@ def write_points(
 
 def to_zipped_point(zf, filename, xyz, color=None, radius=5):
     """
-    Writes a point to an SWC file format, which is then stored in a ZIP
-    archive.
+    Writes point to an SWC file in a ZIP archive.
 
     Parameters
     ----------
     zf : zipfile.ZipFile
         ZipFile used to write the generated SWC file.
     filename : str
-        Filename of SWC file.
+        SWC filename.
     xyz : ArrayLike
         Point to be written to SWC file.
     color : str, optional
@@ -557,7 +555,7 @@ def to_zipped_point(zf, filename, xyz, color=None, radius=5):
 # --- Helpers ---
 def get_segment_id(swc_name):
     """
-    Extract the segment ID from an SWC filename.
+    Extracts the segment ID from an SWC filename.
 
     Parameters
     ----------
@@ -578,7 +576,7 @@ def get_segment_id(swc_name):
 
 def get_swc_name(path):
     """
-    Gets name of the SWC file at the given path, minus the extension.
+    Gets SWC filename at the given path, minus the extension.
 
     Parameters
     ----------
@@ -588,7 +586,7 @@ def get_swc_name(path):
     Returns
     -------
     name : str
-        Name of the SWC file, minus the extension.
+        SWC filename minus the extension.
     """
     return os.path.splitext(os.path.basename(path))[0]