I finally got around to installing 12mm laminate with a high grade underlay. I bought a laminate to carpet transition strip that was made for 12mm flooring. When I went to install it the transition strip didn't touch the subfloor as the underlay added 2-3 extra millimeters of height to the laminate. Even with alot of force I cannot get this stip to sit properly. Without the underlay everything fits perfectly.

Brief description of this transition strip. Basically an L shape where the floor fits under the lip on one side and the carpet butts against the opposite side. The whole assembly is then glued and/or nailed to the sub floor.

I dont know if im missing something obvious as I have never heard of anyone else having this problem.