I know these aren't after-market, but maybe one of the after market manufacturers has something similiar....
Savage has designed a Muzzlebrake that can be rotated open and closed. Shoot it open when running a lot of rounds through it at the range....when hunting, close it.
The Browning BOSS system now has a CR attachment. CR stands for convention recoil and the muzzle blast/sound is also conventional.
