I have a vortex 3x magnifier that I got just to test the concept and unfortunately, the magnifier has a similar size eyebox to the ACOG. A higher tier magnifier might be better but I really have to get up on it to not have a ton of shadowThe eyebox has kept me away from any LPVO (that I could afford anyway) though they do seem to be improving steadily.
Part of the charm of a carbine has been shortish range snap shooting, especially from funky positions, hate to give that up
but I past 40 and my eyes are finding all manner of creative ways to suck now, so I came back around to the magnifier idea.
I guess for a couple hundred bucks I should just try one and see how it works.