Maybe my concern is unfounded in that case.
As for suppressors, it's size, weight, and signature reduction. I haven't found any flow-through designs that compare to higher-end baffle suppressors in those categories. My rifle is enough of a pig without hanging a 20oz OSS can on the end of it, which won't even suppress as well as a 12oz baffle can. Especially with an adjustable gas block to mitigate the increased backpressure, I don't see the point. I'm really interested to see what comes of the technology in the next few years, though, especially with advances in additive manufacturing.
Thanks for the input. I know the weight and sound reduction is better with some of the sealed cans. My .308 cans are 17 oz. but they are bigger diameter than I'd like (1.75" on my model). I'm more concerned with reliability and how much fouling ends up in the gun/mags and gas in the face. For me, hearing safe is all I'm really interested in since at any real distance (I'm not a fan of subsonics since they are effectively pistol rounds at that point) the signature is reduced enough to make it very difficult to locate position.