I have added those numbers to the glyphs table but i don’t know how to make it works this way.
I’m not sure about what you show in the video but I would suggest a glyph names like this:
The go to font info > features and hit the circular arrow button to update the features. There should be a feature “sups” that has looks like this: “sub zero-ar by zero-ar.sups;…”.
Yes, this is what I want, but how to make this feature work automatically with these glyphs are positioned directly above the glyph?
This is a bit complex. It need some contextual kerning.
What font do you use in the screencast?