I missed that..good for you, most who are concerned have done other methods of attachment..or other chronographs. Seems like a big freak out over an easily solvable problem. I don't understand the brake on, then taking it off shooting groups & chronograping. I have a Area 419 thats hand detachable instantly for that endeavor, if I so chose on my 6 Dasher, which is very accurate with the brake on. I could out of curiosity, take it off and check velocity and group size, but I'm happy with it as is, more accurate than I require, for my shooting.
But I only remove it to clean it. My muzzle breaks are always on when I'm shooting on the rifle that they are installed on.. I don't care about the velocity or impact change with them off. All the variables in all the electronics, bullets, barrels, powders, primers, cases, have to come together, confirmed and adjusted at 650 yds and then confirmed again at 1000 yds. In the end the target let's ya know. If I were bench rest shooting in competition I may not have a brake or install a tuner. Anything you add or take off a rifle barrel can and often does change group size and location of groups.