On huwiki, FlaggedRevs review often takes months and most mentor questions are some version of "why aren't my changes showing up?". Maybe there should be a "request review" button somewhere on the interface, which sends a stock message or a notification to the mentor. (This would require the mentor to have reviewer rights, which I assume most mentors have.)

Admittedly this is not really a solution to the problem of communities wanting workflows that they don't have the capacity or interest to properly operate, but maybe better than nothing.