Then I realized that Infinity War is not the culmination of everything, Avengers 4 is.
Well, sort of. But my understanding is that, although they removed the "Infinity War" title from 4 and have said that 3 and 4 aren't just one long movie split into two films, they are still really two essential parts of one story. So I think the proper way to view it is along the lines of 3 being more or less the "beginning of the culmination" and 4 being the "ending of the culmination," for lack of a better term.
But still, nothing wrong with your plan. Well, except one minor (truly) detail:
So my plan is to do a huge rewatch before Avengers 4.
And since I plan on doing a (mostly) chronological re-watch, it works out well. I can start with Captain America, then go see Captain Marvel in theaters, then move on to Iron Man etc.
Well, no, not Captain Marvel. That comes out
after Avengers 4.