I'm not aware of any scientific testing of otherwise identical LW and HBAR barrels with and without cans, but I can say that in my experience there are so many other variables that can affect POI shift that it would be hard to isolate barrel profile as the single cause of shift. But I understand why people think that logically a thinner barrel will bend more with a weight on the end, and therefore POI shift will be affected more. If I was still doing that kind of thing it would be an interesting exercise, but to be valid it would really require multiple examples of each barrel and the can in question, so it would probably be cost prohibitive. But incidentally, a shorter LW barrel is going to bend less than a longer one when a can is attached.

I'm not a fan of cans, and I'm even less of a fan of moving them around all over the place, although if you are going to have a can I do think it makes some sense to try and put mounts on the various guns that could accept the can if needed. Again, my experience, but I find that most people that buy cans wind up never shooting with them outside of the static range because the can is heavier than they thought and not as quiet as they thought, and when shooting around a bunch of other people not using suppressors you still wind up wearing hearing protection anyway. Remember earlier when I mentioned people stripping extra weight off of their guns on TD3? Yeah, that can is the first to go. Although I did manage to get through 3 days of an EAG class with a 300WTF upper wearing the can for most of the class.

If you simply must have a suppressor, I think the best route is to leave it on one gun and set that gun up as a dedicated suppressor host. But I'd also probably choose muzzle devices for my other guns that can accept the can if needed. So, for example, if I buy a 10.3" LW DD upper (or a 14.5" LW barrel cut down in order to maximize the gas port size) and set it up as my dedicated host for a Surefire SOCOM762-MINI (which, incidentally, would be my #1 choice for a can by a huge margin, and yes it's a 7.62 can that I would put on a 5.56 gun) I would use a brake mount for that gun to minimize wear on the blast baffle and I would use Surefire flash hiders on my other guns just in case I want to move the can for whatever reason. I'd even put a Surefire brake on my competition gun because (a) they are very effective brakes anyway and (b) if I suffered a brain injury and decided I wanted to put my can on that gun I could.

So I say all of that to say this, which is that again barrel profile just doesn't matter outside of precision shooting. As much as some people would like to try to make an issue of it.