Via dotnet/runtime#55744 (comment)

for autoTypeSafeEnum I would need to split/duplicate the UnionOrTypeSafeEnumConverterFactory as well though - is this what you suggested?

I meant to supply 2 flags to the factory as ctor args which individually control whether to
a) allow automatic Type Safe Enum conversion
b) allow automatic Union conversion

In general, I'd assume that if you like convention based things, you want to start with both behaviors in place.

However, you might want to be able to disable individual behaviors.