There where a few places where I though about adding alternate decompositions. But I wasn’t useful enough to actually implement it.
There will be some font file that only have the spacing glyphs but that will only be temporary as I only recently switched over to only use the nonspacing accents.
The .cap accents don’t need to be mentioned in the glyphData file. On composition, it will look for glyphs with a .cap and .case suffix and will use that glyph as a component.