Nope, nothing that I'm aware off.
Would be cool, as some stem creator tools use that formart.
There’s plenty of utilities on PC to convert from/to ALAC. First one that comes to mind is Movavi ALAC Converter.
https://www.movavi.com/support/how-to/how-to-convert-flac-to-alac.html
Understandable, sorry for confusion.
By the time you've used software to separate stems, you're not going to be able to notice the difference between ALAC & AAC
But one may want to produce his own stems and in that case ALAC would be good. Or flac if NI would updated Traktor to be able to use flac STEM files. It would be simplier way than wait for MS to reintroduce ALAC support to Win.
yes, that would be the best way