I just bought a new 5th Wheel. I have had one before and it came with an old hitch (don't recall the brand but it was nothing special). My new 5th wheel has a GVWR of 12,000 lbs - Dry Hitch of 1625....
Every hitch makers web I've been on also recommend a tug or pull test .... they do so for a reason and has nothing to do with what brand someone else owns or any CYA on their part.
Your recommendations that others with a B&W can ignore their hook up procedures is reckless at best and just your opinion.