Hi, J.!
I also have twins-mine are girls and they are 3 now. I had those jumpers for my girls when they were little and they loved them! I never had any problems with them falling out, getting hurt or the jumpers falling off of the door frames. I would put my girls in the same doorway, far apart enough to not ram into each other, and let them bounce to their heart's content. I used to put them in the doorway to the kitchen and let them bounce while I cooked meals. The girls and myself loved those jumpers, and I wouldn't hesitate to use them for your boys.
S.