I had a similar issue with my theater seating (Thomas Payne) that went where the sofa was. With enough clearance from the wall to allow reclining the front feet would hang over the edge of the slide floor an inch or so. As a result the front rubber feet on the seating were just kind of hanging which caused the seat to be slightly low in the front. I had some laminate flooring scraps that I cut into roughly 3” squares and used them as shims near the front edge of the slide and screwed thru the seat frame, shim and into the slide floor. They’ve been in place since late 2019 with no problems.
Here’s a pic of the install partially complete.
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Cheers,
T_
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks