Checking KanjiVG versus the SKIP values produced by
https://github.com/KanjiVG/kvg/tree/master/cmd/skip,
some of the groups in the following are not grouped in KanjiVG:
Top of 布右左
Top of 石
Top of 鳥
Top of 食 - this also applies to subelements.
Left/right of 非
Above/below of 虍
It would probably be better to group these into one thing.