Your questions go beyond my area of pay grade. Muzzle rise on the piece is non-existent, AFAIC. But realize that I shoot lots of big bore, lightweight rifles. I'm pretty recoil proof when it comes to long guns (and equally recoil shy when it comes to handguns).
Surprisingly, given my affinity for hard hitting long guns, I lack the upper body strength of many. Thus, with the suppressor on the Grail, I WILL tire after a time. I cannot run the gun an entire class day from the "ready" position easily. Toward the end of the day, you'll see me "cheating" with the buttstock under my armpit in the ready. It's just the way I'm built. God gave Denny and Pat muscles....he gave me money and women!
Cannot tell you the Surefire muzzle brake characteristics, sans can, as I've never actually checked it out at night. That is, however, a reasonable request on your part, given the fact that I've referenced it as my go-to carbine. The piece lives where it lives without suppressor attached specifically because of the legal problems defending yourself with Class III weapons. So, I should be able to answer that question and will, the next time I have it in the field.