You know that Adobe doesn't talk about unreleased features (unless Thomas or Eric are feeling talkative).
there is always a chance for somebody feeling talkative... and not being able to resize healing brush area if you did not get its shape/size right from the very beginning is PITA.
I agree 100% with this critique. Some sort of + and - (add, erase) facility is sorely needed.
I've noted the feature request.
I also think you're overstating the issue regarding not being to resize the brush strokes at present. Yes it would be nice to be able to resize but it's certainly not a dealbreaker. There are other effective and efficient workflows: Namely, if you need to paint more/refine an area, just paint a new stroke. This is easiest to do in ACR by hiding the overlay (shortcut: press V). In this mode, painting spot strokes is similar to Photoshop's spot heal brush (accumulate as many strokes as you need over a given area, and let the source be chosen automatically). If at any point the auto chosen source mode picks something bogus, try pressing / key to have it pick something else.