I was looking at buying a complete 9mm upper to go on a Glock lower SBR. I ran across some David Defense 7.5 inch keymod handguard, and a 4.2 inch ultra slim keymod handguard. This SBR will be primarily running suppressed with an Octane 45, but I want to have the availability to shoot unsupressed as well. Does anyone have any experience with David Defense? I don't know anything about them so wanted to hear some feedback about them before just jumping in. I like the 4.2 because of the shorter OAL but worry that the ultra slim handguard will be too small for the Octane to fit under. Thoughts?