I'm the guy KKF did the Lavang for recently. I took the gun out into limited visibility conditions (dark) to include a misty rain. While shooting it I noticed that there was some muzzle rise, BUT, I was able to control it enough to do double taps on a paint can at 25yds reliably. I would roll the can up the hillside, and then push it up some more or stop it.
Regarding the job KKF did, upon inspection I could see that the park job could have been done a little better and on the bottom where he did the pin job, there is not a complete fill. Should I send it back? Yepper, will I get it back any time soon? Doubtful. It is functional and that is what really matters, this ain't a range queen.
Flash supperession? I think so. I stood off to the side to watch a friend shoot it. This is mounted on an M4gery from BM. My perception was that the flash is directed into a cone shape approximately 5-6" in front of the muzzle, about the size of a tennis ball. The flash converges upon itself, disappears for about 4", then reappears for about the size of a golf ball. I was pretty happy with that. Side concussion was not anything like it was preveiously. I'm very happy with the performance and look of this "comp", if you can call it that.
I'll put my .02 regarding the limiter, it just looks like you would get a fireball with that thing. The angles would do more to spread out unburned powder enabling more air to get to it to promote ignition.
USMC03 is the main force behind my doing mine. He was happy with his. I was going to pay TomJ to do mine but he never returned emails or anything. I sat on the Lavang for about 1.5 months and needed to get it done sooner or later. HTH
Edited to add images:
Mine