Both my 2005 F150 and my 2022 F150 are equipped the same:
- Line-X standard spray in bedliner installed shortly after truck purchase
- B&W Turnoverball underbed gooseneck hitch
- Andersen Ultimate gooseneck hitch bearing directly on the Line-X
Yep, the ~18 years old Line-X in the 2005 has faded a bit from black to uniform charcoal gray, but after all those years of abuse as a working truck on rural property hauling everything imaginable from mesquite logs and brush to heavy appliances slid across the bed it is without any deep scratches or damage.
No mat used under the Andersen with either, it stays-put, no movement or issues whatsoever.
Years ago I used a bed mat in a previous F150; water and dust / mud / debris collected under it and it was heavy as heck to remove / clean underneath and the bed still got minor paint scratches. I'm happier with the Line-X, YMMV.
Note that the standard Line-X has the same underlying lifetime warranty as the glossy-finish premium versions.
The pic with the toolbox is the 2005 snapped a year or so ago, a bit of dust from my rural road accumulated in the low spots and some residual rainwater at one corner of the hitch (not a permanent stain, there's none of that in spite of gasoline, oil, and diesel spills over the years); the side view with the in-bed socket circled in red is a recent shot of the 2022.
Just sharing my personal experience FWIW.