Comment by BruceEel

Nice list.

Also, hidutil (https://developer.apple.com/library/archive/technotes/tn2450...).

Example:

     hidutil property --set '{"UserKeyMapping":[{"HIDKeyboardModifierMappingSrc":0x700000049,"HIDKeyboardModifierMappingDst":0x700000065}]}'

For my PC keyboard, remaps "Ins" (normally useless under macOS) to something ("PC Execute") I can trap and remap with Keyboard Maestro.