I use the 4’ x 8’ wire mesh stuff. It has the big holes. My tomato plants also get huge so I needed something that could hold them. I have the same issues you describe…I just do my best at keeping the branches held in and if a few get away I will let them grow. If it gets to out of hand I clip some shoots off. I think it is all about balance. I always clean out from the bottom up once harvesting starts and leaves start to die which helps with air flow for the shoots that have fallen from the sides or the top.
Pic is from a couple days ago, you can see the wire …a little bit…lol. Just started to harvest some 4th of July’s, Brandywines and Better Boys so it wont be long before the bottom of the plant get thinned out.