I am making a typeface with the feature fwid which turns all glyphs into full-width versions (provided they have corresponding glyphs with the suffix .full). This works fine. But to support applications that don’t have access to OpenType features, I want to also export a separate font whose glyphs are full-width by default. So I added a custom parameter Rename Glyphs to an instance. The value is like this: “A.full=A, Aacute.full=Aacute, …”.
The problem is that, this doesn’t duplicate the source glyph, rather the glyphs before and after the equals signs are “swapped” it seems. A.full is already assigned to the codepoint U+FF21 and this must not be proportional. I want the resulting font to have the same full-width glyph for both U+0041 and U+FF21, just like when you enable the feature fwid. Is there a way I can achieve that?