Spoke with a very helpful guy @ Long Mountain yesterday. We figured out (with some measuring) that their version (not Gemtech) won't work for my application. Trying to fit it on a TROS 3-lug barrel under a KAC or DD 7.0 FF handguard. I can get it on but, the release lever will be trapped once on.
Gemtech seems to be the only way to go. Heard they stopped producing them. Have to give them a call tomorrow.