My experiences:
I shoot a Harvester 300 on a 223/5.56 AR15 carbine with a 16” barrel. I put on a Silencerco Alpha brake/suppressor mount. Originally I used direct thread but I didn’t like having to wrench off the flash hider to thread on the suppressor. But the brake alone with no suppressor is loud and even with hearing protection shooting at the range from a covered position, I’ll get a headache after a while. I recently put another carbine together and used a three prong FH/Alpha mount on that one to avoid the concussion (yeah I know it’s only a 223) when shooting without the suppressor.
I use an adjustable gas block and I can turn the gas up and down as needed, can even shut it off. Even so there is enough blow back the get the insides of the upper and lower receivers dirty. Just have to clean up more frequently.
I had a reduced power hammer and trigger spring set. I used to run my BCG with an amount of CLP lube that many shooters would say is too much. I did so because it prevented the hard carbon buildup on the bolt tail and inside the carrier. Made clean up so much easier. But one time after firing a lot of rounds suppressed I got a misfire or two...click but no bang. Light primer indent. Took apart the BCG and inside around the firing pin was a heavy sludge, a slurry of oil and blow-back crud. Cleaned it all up and went back to a regular power hammer spring, problem solved. I never had that trouble shooting un-suppressed so, yeah back pressure/blow back.
I really don’t notice gas blow back in my face. Always wear eye protection though.
So in conclusion...adjustable gas block, clean various parts frequently, if you’re going with a quick-attach mount I’d advise don’t use a brake style mount because a. 223 doesn’t have much recoil or muzzle rise and b. it’s going to be LOUD especially with a short barrel when not suppressed and probably pretty flashy too.
I think for an AR SBR, 300 BLK is better suited in that role than 223/5.56. Don't know what chambering you are going with but just throwing that out there.