Originally Posted by OdinIII
I've looked at those options before but it seems to me that the closest to my needs is just the QD base mounted in the front-top slot in the handguard with the light mounted to the top of the HG using the cantilevered mount. This seems to me like the sling would obstruct access to the light controls. Maybe not? I may have to move the sling mount toward the rear of the rifle to make it work.
This is a conceptual problem, not a hardware problem. You're asking to put the two items in what is essentially the same space.
I would suggest something like the below, which I would accomplish with
IWC QD socket recessed into rear of MOE
Midwest Industries MCTAR-04
attached to FSB
configured like the below you'll have just enough room for your support hand on a carbine MOE. Get a Mid-length-gas carbine and you'll have even more room.