RE: Barrel lengths
One of the keys here is that one shot either with OR without a brake will cause hearing damage. Much the same as firing a 22 without hearing protection. So the argument is moot to me in a big way.
And on the thread protector-- not only can it change the impact from sighting in, it can severely change the barrel harmonics. What may shoot great with the brake on may suck with it off. The only way I see it is either one way or the other. I don't think you can have it both ways. You either have and use the brake for load work, zeroing and hunting OR you deal without.
Jeff