the brake vs. break controversy, has been pretty interesting the last 30 years, initially I think the original use was compensator, as in Cutts compensator on Thompson Subs.
Not saying which is correct, but from a discussion point of view.
the formula for calculating recoil does not use pressure in its calculation.
in the vector analysis of the forces, there is no negative vector that would suggest any type of braking. the amount of recoil reduction is due to less ejecta bearing against the dia. of the end of the muzzle.
had this discussion with the folks at JP in connection with their "Sail" type brake, and their position is that a "jet thrust" is produced and the larger baffles capture this.
My reply was show me the math.
recoil is independent of pressure,
however there is a substantial "break" in the direction of the escaping gases.
