Indeed, the question was actually rather specific to foliars of beneficial microbes, not just foliars. I wasn't comfortable with my response after reading yours, so I did some digging and sought out some answers. First, I tried to find out if there's been any kind of study done on how JMS or true soaps affect soil microbes, and not having a whole lot of time, I really didn't find anything (if it's out there). I do use foliar applications, just not often, and ACTs are applied in this manner even less often.
So I contacted one of the cats who runs KIS Organics, they also work closely with Microbeman, and the elder of the father & son pair is cited by one Elaine Ingham in her book on AACTs, so I consider theirs to be expert recommendations. Remembering that I do *not* regularly use beneficial microbe foliar applications, here's the brief exchange.