I understand enough of physics to have an idea on how forces are redirected and wave propagation for sound, but the proof is always in trying it and measureing both the forces and the sound level at different locations.I shot at Wenatchee and there was an experienced 1000 yd F-Class shooter there with a brand new $5500 rifle there with a Vias brake. He shot the rifle with the brake and then took the brake off. He could not notice the difference in recoil. He took the brake and threw it as far as he could throw it. That is one brake I have not purchased. I can't tell you why the design is less than optimum.
I have two type of brakes, BOSS and custom on rifle by a smith. Both reduce recoil. Both are louder, especially for people standing next to the shooter or the bench over.
To reduce recoil, ports need to be directed back. To reduce muzzle rise, need ports on top. To reduce sound blast at the shooter, they need to be directed forward. To me the best is to find a balance. Thats the theory in a nutshell. Very elementary.
Lately I have seen various designs that attempt this, but I have no experience with any, and I have not seen measured data.
If someone has it, please share