In reply to Indesign ALL CAPS button: what OT-Features does it apply? What is "desired behavior"?:
It depends on what's in the case feature. I agree with you, figures should be "lining." When going into a font (with permission, of course) I usually add this to the case feature.
This also means adding a bit of spacing to the numbers in the cpsp feature, but for me, not as much as I add to the letters.
Since the InDesign "all caps" routine calls two OT features, one really needs to do work in both places.
Other things to consider are the parens, brackets, quote marks, etc. Dowding had a list o candidates in Finer points. I also set the Spanish inverted question mark & exclam to work with caps in the font, then make up a lowercase version to use when they don't start a sentence. This too can be automated.
I think the reason I wind up doing a bunch of this work is it only makes sense for a compositor, a user of type, not the designer/publisher. There are too many different workflows possible, too many text editors, layout programs, and varying style requirements. So yes, it can all be done, but I'm not really sure the font publisher should.