He's right, the pool of people that will buy a warp fed rig is very small.
I mean if you have a low end $650 dollar Bushmaster or DPMS then
I can do it with both hands, but I can't support the gun weight in my off hand right now.
realistically everything that has a warp or modified for warpfeed will likely sit. Which is 2 or 3 of 3 automags in the picture.