Moving Driver Seat Back - on top of carpet or under?

[lks dcvn]

I'm doing this mod on one of the trucks I'm building.

For those who have done this - did you put the steel plate under the carpet or on top of it? I plan to weld nuts to the bottom of the plate so I can install them front legs like OEM. I also plan to place some hard rubber (possible an old body mount puck) to help with distributing the load over a larger section of the floor where the front feet are. This really does help with the leg room on these trucks - I have 2 additional inches to move back now.

Links for reference - here and here.

I have everything mocked up now - just wondering if I need to plan to have the plate visible or not after I get my carpet installed.