I like mulimc. super easy to manage mods (I use a performance boosting modpack that has like 25 mods in it) so it automatically keeps that up to date
also the official launcher had issues with my VPN where if it was connected it wouldn't load my skin and I couldn't even split tunnel it, multimc doesn't have that issue
extreme battery saver already caps brightness, but I can defiantly turn on extra dim to keep of a bit lower