Pitbull ears stand almost immediately with no huge effort on your part because they are VERY short.
You need to remember that ear cartilage (which is what enables you to get a standing ear) hardens over time from the bottom to the top. So time is a factor in how stiff the cartilage is--but that's why you sometimes (as in often) get ears that clearly don't stand as well half way up the length of the ear. The cartilage stiffens over time and you just keep posting until the cartilage is actually stiff enough to hold the ear upright.
Sounds like you are making sure that the little ear flap is positioned correctly but getting ears standing properly all the way is definitely a process--and you probably are overthinking it to some extent.
How old is he now?
As far as what puppies can do with their ears--they can swivel them to better catch soft or distant noises. they can fold them down in a zillion different ways. And they can plaster them back so that they look like a seal. And ear carriage definitely is a good clue to how a dog is feeing about what is going on around him--and that's all normal.
Hope this helps...