by which point is would it be impossible for the French royals (lets limit it to a change in Royal (geo)political positioning for now) to stop the Revolution from happening? How far back do you need to go with a PoD to dodge the 'unpleasantness' ? From what I can read Louis XVI did try to nudge towards a more reformist course, but was more or less blocked by the aristocracy from actually succeeding in more than inadvertently giving the population the tools needed to revolt (From what I can read it was more about being badly advised than active malice or personal incompetence, since a large part of the things seemed to make sense, absent 20/20 hindsight) before they blew up in his hands)