For entirely unrelated reasons, I have looked at some of the related code in
the last few days. While most people are unlikely to miss any crucial
functionality since it is not even enabled in the default build, there are two
comments of the "this feature not yet implemented" kind in the GETINFO section
of the infinality diff which is not in the alternative code path. The
alternative simply does not mention anything missing.
I hope some of these knowledge in comments, probably also alsewhere, are copied
over before its removal. There are people who want to know what Apple/MS does
which FreeType does not (yet), even if those corners are practically
unimportant and/or nobody is doing anything about it any time soon.
FWIW, those two "not yet unimplemented" features have been not yet
unimplemented for 20 years :-).