Has anyone used LMT BUIS with an optic? How did it work out?
I am assuming you mean co-witness on a 1x optic? If so, I have tried a friend’s MK18 clone and the LMT BUIS was not appreciably more obtrusive than others I have tried. This, of course, was achieved with the proper spacers for a lower 1/3 co-witness. HTH.