I just installed the beta and briefly tested the predefined functions, which are a great addition to Sigil!
Am I right in assuming that unlike the Calibre function mode, users won't be able to easily add their own custom functions, unless they add them to
fr_utils.py and
functionrep.py?
If so, could you could you please briefly document the interface in the Plugin Framework guide?
If it's not too much work, I'd recommend adding two additional custom functions that Kovid described in the Calibre function mode documentation.
Using a spelling dictionary to fix mis-hyphenated words
Auto numbering sections
I also have a minor nitpick about the GUI. On my Windows machine, both the X and 𝑓 buttons are rendered in a color that is usually used for disabled buttons. It might be helpful to display them in another color that is also visible in dark mode to indicate that they can be clicked.