My default figure style is old style proportional. Glyphs can generate the features alright, but the sidebar list is not reflecting this configuration. Is there any way of having Glyphs showing this correctly?
What do you mean, it’s not reflected? It is correctly reflected. Your default numbers (Decimal Digit) are designed as oldstyle proportional. You don’t have separate proportional osf figures, so why should they be marked as checked in the glyph list?
Well, that is certainly one way of looking at it.
I think Glyphs only uses the glyph names to build those category lists.