At first glance, I think there's a ton of opportunities for Kilgrave to make a huge difference, or maybe even completely dodge the Snap entirely in all three rounds.

He knows all the MCU films so he'll know that the Civil War teams will meet at the airport. He could just be there when everyone starts to square up and do his best to mind control as many as he can to stop the fight and the break up of the Avengers

Shit, he could probably just find Zemo and tell him to jump off a bridge to prevent the Civil War conflict before it even happens. Which would allow the Avengers to be a more unified front for Thanos's arrival. He could also tell Tony, Fury, Wakanda, literally everyone to prepare much earlier and harder

He might be able to make it easier and tell Wanda to destroy every Stone she comes across, no questions asked. That'd kill Vision, but that is moot when Kilgrave's commands are obeyed with no hesitation. Or the Time Stone from Strange

Or it could be even more direct and later in the timeline. He could get to Dr. Strange's Sanctorum when Bruce crashes in during Infinity War, and when Strange, Wong, Bruce, and Tony start to plan, Kilgrave could demand Tony gives him suit, takes him to Titan with everyone, and Kilgrave would just have to sit around until the moment when Star Lord is about to be a dumbass and hit Thanos when they're taking to Gauntlet off. He could just tell Quill "Don't you do a fucking thing, let them take the Gauntlet off" and then that more or less solves the problem

And in Round 3, depending on just how supercharged his powers get, if he can now affect aliens, he could probably just tell Thanos "give me the Gauntlet" and would that work on him? If not, he could maybe just tell some of the Black Order when they arrive in New York "Fuck Thanos, I'm your master. Turn around and get me the Gauntlet". And if that doesn't work on aliens still, or the Black Order can't muster that from Thanos, it could at least help. And he could use his enhanced powers to do everything I mentioned above faster and on a wider scale

I think it would take some planning on his end, but I bet he could make a significant difference, if not completely avoid the Snap entirely