I'm looking at the ones that go past the gas block but don't require d ring or nut removal

Sorry, got interrupted posting. And I'm wondering if anyone had mounted then

I believe you are limited to the ones that slip into the Delta ring assembly and ring that sits behind the gas block. That's what holds the handguard in place. It's the spring action of the delta ring that secures the "Drop In" guards in place. Otherwise, you are looking at a free float system that requires a low-profile gas block. This system usually requires removal of the delta ring assembly, and often the original gas block.

There's the Daniel Defense, Troy and I think Midwest Industries. I went with the Troy. It retains the delta ring, but it does not have much to do with securing it. There are steel shims behind the handguard that grip the barrel nut and center the whole thing. See the other thread on this topic for pics.

I think it would be helpful if you provided a link to the ones you are looking at.