GPOS system of double-stacked diacritics?

I’m having a look at this now. There are a few issues:

  1. I created the @CombiningTopAccents class, but updating the features also puts a class by the same name into the ccmp feature. Should I just delete the class outside the ccmp feature?
  2. Is there is way to write the context so that the anchors are used both when the glyph comes before @CombiningTopAccents and when they come after @CombiningTopAccents?
  3. What do I do with the pre-composed glyphs? I can’t use the new anchors to place those diacritics, so do I delete them?

Ping @GeorgSeifert