Folks, a couple thoughts here.
1. When I took the factory tour back in May 2022, I didn't see any boxes to support a table leg built in to the floors. The floor seem to only have deviations for the entry step, the right rear storage drawer and the wheel wells for the rear duals. I've attached a photo of a stack of various floors before the insulation and wood sandwiching. But,,, that's not to say the process hasn't changed over the years.
2. In the 1st pic at the top of this thread we haven't called out the fact the hole shows all wood and steel.... No foam insulation. So maybe the process years ago was to build a wooden box? Interesting.
Larry