For tabs/spaces work, currently app has the weird checkboxes in the "File Properties" dlg.

I suggest to make it like in Sublime Text and CudaText.
- make the "Tabs" or "Spaces" cell in the lower statusbar
- on clicking this cell, show dropdown menu with several check-items, and/or commands
CudaText has this
- if "tabs as spaces" on: statusbar cell name is "Spaces: 4" (4 is tab width)
- if "tabs as spaces" off: cell name is "Tabs: 4" (so cell is renamed)
- dropdown from this cell shows items:

For tabs/spaces work, currently app has the weird checkboxes in the "File Properties" dlg.
I suggest to make it like in Sublime Text and CudaText.
CudaText has this