I think you're over-thinking it. The MAlign's strategic objective is to break up the SL and neutralize Beowulf so the pieces can coalesce around a nucleus that will be receptive to their ideas of "uplift." Mesa, with the tidal wave of corruption it's causing, was always a means to an end, and they fully intended to throw it away in the end game. Consider:
Mission of Honor, Chapter 38.3 wrote:By now, the Darius System's total population was in the very near vicinity of 3.9 billion, of whom just under two billion were representatives of one of the alpha, beta, or gamma genomes the Alignment had worked to improve for so long. The remainder of the system population were genetic slaves, but the conditions of their slavery were very unlike those which obtained elsewhere. For one thing, they were treated far better, without the often savage discipline slaves often received elsewhere. In fact, the Darius System was one of the very few places where the Mesan Constitution's official legal protections theoretically intended to protect slaves from gross mistreatment were actually enforced. For another, they had a much higher standard of living. And for yet another, they formed the backbone of a highly trained, highly skilled labor force which had earned the respect of its supervisors.
The MAlign doesn't care one iota what happens to Mesa or what steps others take to clean up the mess as long as they get their strategic objectives out of it: breaking up the SL, neutralizing Beowulf and having a seed that the new order will coalesce around.
Once the MAlign leaves Mesa I suspect that the political situation will develop in a hurry. Remember the situation in Crown of Slaves where one of Mesa Pharmaceutical's managers wanted to cut down on the wastage of slave labor on Verdant Vista by installing automation, and got overruled by someone who we can assume was on an inner layer of the Onion? Without that kind of interference things may move in a productive direction if people let it.
As far as I'm concerned, what needs to be done with Mesa is cordon it off under a "what happens on Mesa stays on Mesa, everyone else keep their hands off," Beowulf and Torch being the exceptions and the Ballroom given the task of cleaning up the cut-off tentacles.
Darius is the same: once it's discovered, cordon it off and let it develop its own way. As far as I can tell,
Darius is Leonard Detweiller's vision, not Mesa.
Once the Renaissance Factor is hauled into the light, I don't think much else really needs to be done.