HTT construction; What is good vs. not so good

I've watched all the video I can find and Jayco does not show any clear images of their inner wall assembly. It appears that the foam core is routed out and aluminum (?) square tubing/C-channel (?) is inserted in the dados. There was no clear pictures of the vertical pieces being welded to the horizontal pieces before the lamination process.

Also I could find no clear images of how the walls are attached to the floor.