Level 7 bolts will do fine with the fast hoppers we have now. The problem comes when you run the hopper low. Then the level 7 can't compensate for that bouncing ball in the stack. That is where the level 10 comes in.
The operating pressure behind the ball isn't the issue with breaking balls. If that was the case, then some of the other guns on the market would blow the balls all to pieces, because most of them have much larger breach pressures than even a mag has.
The gentle hit in the first 1/4" of travel is why the level 10 works to prevent chopping. After that distance, the push force increases dramatically so that it is back up to levels of the level 7 or even higher because the chamber pressure is higher than a level 7 mag. Most level 10 breaks come from trying to push tight fitting balls into a barrel that is a bit tight, or at least not loose fitting. Almost all guns with gentle bolts have the same light push for the entire bolt movement, so as long as they can move the ball, it will get gently pushed into the barrel. The mag level 10 bolt only does that at the beginning of the cycle. After that it will try to cram that ball into any crevis it can. So, a level 10 bolt will prevent chops, but not barrel breaks.
Except for the Automag in front, its usually the man behind the equipment that counts.