It seems like under some cicumstances it is not possible to delete glyphs in a .gfs file at all (the "Delete Glyphs..." option is grayed out). However it's not clear to me, why and how I can change it.
Update: It seems like Glyphs can't be deleted when TrueType curves are selected. Still not sure if this is a bug or not. Also, master outlines for variable fonts are getting deleted when you change from TrueType to PostScript curves.
Last Edit: Apr 11, 2021 11:42:17 GMT -5 by daveman