Wrong group name in AFM

When I export a AFM from Glyphs some group names seem to be wrong. For example, my group name for all superiors is “zero.sups”, but in the AFM it’s “a.sups”

AFM files do not support classes. So I meed to flatten them. As I can’t rely in the name of the class, it uses the first glyph from the group.

So what would be the best way to get the kerning from Glyphs to Fontlab?

Glyphs Import.py in https://github.com/schriftgestalt/Glyphs-Scripts

It does the same and changes the Kerning groups.