I don't see why "having to settle for macrostates" is anything more than the observation that we use heuristics. Maybe because I don't understand your statement

I don't see why "having to settle for macrostates" is anything more than the observation that we use heuristics. Maybe because I don't understand your statement "our brains and bodies do have an artificially imposed uniform distribution over microstates"? The issue seems more due to the number of states than anything about their initial distribution. Caveat that I have read the post but not the paper.