If trapping him in a time pocket was an option before, I would have done it. And trapping him in the quantum realm might be difficult considering he has the gauntlet by this point and at least one stone giving him the power to decimate an entire planet on a whim.
From what I've gathered, the pieces I've managed to unravel so far, he has entire armies at his disposal. That he can send in to subjugate worlds, before he ever shows up to order a purge of half the population. Or, at least, I saw him do that to quite a few Earths. It wasn't pretty.
So that might also be...problematic. Catching him alone to trap him.