I think you will likely be good to go, man. You REALLY should go out to a range somewhere that allows you to shoot at night, well after the sun goes completely down, and test out your primary HD carbine. Shoot it without the light activated, and with the light activated. Also definitely try different types of ammo, as ammo DOES make a huge difference in muzzle blast and flash.
If it's ALL really bright, and if your light isn't enough in your judgement to nullify* the brightness of the muzzle flash, then you might want to get an actual weaponlight, such as a Surefire X200, X300, M300 Mini-Scout, etc... basically one that's a lot brighter (I have no experience with what you're running right now, I'm just making the assumption that the weaponlights I listed would be brighter).
* Not sure if I used the word "nullify" in the right context here, LOL:p
You should WATCH THIS VIDEO I MADE recently of my Surefire MB556K brake being used on my BCM 14.5" mid-length at night outside in the dark. Ammo being used was PMC 55gr FMJs, and the flash isn't all that bad. The second half of the video is me firing my Surefire suppressor to see the difference between unsuppressed and suppressed fire at night or in low light situations, which is actually the point of the video.
Hope this helps. If not, let me know if I can explain something else in better detail for you.

