Apple finally released the 11.2.3 update for Big Sur. I have installed it on my iMac and restarted a couple of times just for drill. All seems to be fine. Apps are very responsive. All of my main workflow Apps seem to work fine. There still is a little wonkiness with the Finder, but I have come to believe one of my Apps is the problem, not the Finder. There is no Combo Updater anymore, so don’t wait for it to appear. You just have to update from within the Mac.