Thank you for posting this - the 4800 lbs Rear axle capacity may help answer a lot a speculation on the rear axle used in PowerBoost equipped F-150s in numerous other threads, looks like the Rear GAWR spec below may really reflect capacity instead (otherwise where does your 4150 lbs Rear GAWR...
When I placed my order back on 1/15/22, the salesman said that the spray-in bedliner I had in my order was on "commodity hold", so they took if off the order and said their shop could put it on if I wanted it.
Which may work out well, I think I might choose an alternative to the spray-in liner...