Most of “API 2” is window dressing (I’ve said this before)
We could have achieved most of this on our own with subclasses & defining our own events and then just use our subclasses instead of the built in ones.
The things that really matter - bug fixes in the C++ framework code, fundamental language changes and additions like Generics - arent things that API 2 will or can do anything about
because its not altering the really low level things
The single exceptions to this are the addition of VAR as a synonym for DIM (which is about the MOST trivial change to make in the compiler) If it took more than 5 minutes to add there was something wrong as DIM was a very simple item in the grammar from what I recall
That and moving folderitem to newer apis on macOS are about the only really low level changes that occurred
MOST of folderitem was already updated in the iOS framework and needed to be moved over & adopted for desktop - there was work required there
Heck even API 1.0 folderitems got this update because - wait for it - the same C++ code underpins them both 