Dodge/Rams Body Builder guide allows drilling/welding the main frame rails on '03 and up Dodge/Ram hydroformed frame rails.
Drilling/welding the top or bottom of the tube rails can void the frame warranty.\
We also don't know the truck work history.
My 2500 '03 5th wheel/GN hitch brkets were welded per Dodge Body Builder guide in '03 and no issues with frame problems in 380+k miles carrying up to 3600-3800 lb hitch loads on my GN ball.
Using a gvwr based payload in the bed shows the fallacy of using the gvwr payload sticker as a in the bed payload which of course overloads a LDT rawr in most cases.
It'll be interesting to see the truck owners decision on how to go forward on the trucks problem.