I'm a little unclear on whether the OP was referring to using a muzzle brake as a suppressor mount (where the can completely covers the brake) or one of the newer suppressors with a built in brake on the front end like the Silencerco Scythe-Ti or TBAC Magnus options. Regardless, I have both types for different rifles.
One of my .375's, a 20" Ruger Alaskan, is threaded. On that rifle, I have a Griffin EZ Brake which serves as a mount for a Rex Silentium MG7. It's still fairly loud with the suppressor, but much quieter than it would be with a bare muzzle. The MG7 is a small suppressor, so it's expected that it won't be particularly quiet. The fact that both the can and brake are bored for .458 doesn't help either when it comes to maximizing suppression. Balance is affected, of course, but not too badly, and overall length with the can is similar to a 26" barreled rifle. I can still see the iron sights over the suppressor, if needed. Without just the brake, the rifle is not substantially louder than my .375 with a bare muzzle to the shooter. I'm sure it's a different story off to the side though. The EZ Brake is very small and isn't a particularly effective brake; it's main purpose in life is to provide a quick, secure means of mounting a suppressor.
I'm in the middle of building another .375 Ruger, detailed in another thread. That one will initially also use the MG7, but eventually I'll probably pick up a dedicated .375 can made from titantium for it. That will be a larger, yet lighter, can in an effort to quiet it down a bit more. I'm considering an 8" Ecco Accipiter-Ti, unless something more appealing comes along between now and when I buy one. Can't have too many suppressors.
As far as suppressors with a brake on the front, I have a .30 caliber Silencerco Scythe-Ti that primarily lives on my .300WM. It mounts on a TBAC CB brake and has the included anchor brake on the front, so I actually have a brake on each end of that suppressor. As described, that setup is impressively quiet, especially considering that it's a fairly small can. It's not much larger or heavier than my TBAC Ultra-5, but much quieter. The anchor brake does reduce recoil based on comparing to shooting the same rifle with the Ultra-5. I haven't used the Scythe-Ti without the anchor brake, so I can't make an apples to apples comparison of it with and without the brake. Flat end caps are available, I just haven't felt the need to buy one. Maximum recoil reduction is achieved by just using the CB brake with no suppressor, but the blast from that brake is obnoxious. If I were hunting with that rifle and couldn't use a suppressor I'd definitely remove the brake.