Not trying to be a ####, but I would love to see the difference between a brake set up for 2 different 338 lapua loads and then switch the loads to see it it makes a difference. Or compare a tuned brake to a standard brake. My bet is that it probably can't be felt.
Go to the precision rifle blog and read the part where they compared brakes for different calibers on the same rifle and there was virtually NO difference.
I don't doubt that a brake could be tuned. But I would love to see the test results from a 3rd party that demonstrate if or how much of a difference there was.
Apparently those JEC brakes are amazing. IMO ugly. But apparently they work very very well.