In a variable font it’s easy for me to apply a ligature at a certain point in the designspace eg
#ifdef VARIABLE
condition ...
sub a b a_b.liga
Usually to do this sort of thing in static exports (swap a glyph on a condition) I’d use Rename Glyphs, but I think that is single glyph substitution only? I’m trying to implement a її ligature with three dots that overrides the contextual alternate with four squished dots, only at small optical sizes.
I guess I can add it to a build script if necessary (check axis location of what I’m exporting, if it matches, move the ligature substitution in rlig out of the condition) but I feel like I’m possibly overlooking a simpler / generally cleaner way