Does anyone have knowledge or experience of the frames Lance is now using? I have been looking at a 2014 Lance 1995, and have been crawling all around under that TT. I'm very worried about the longe...
Properly designed and built cutouts in the webs of structural members are not an issue if the members were adequately designed for the loads the manufacturer decides to specify. Aircraft structural sections are full of lightening holes and they work just fine.
You should also note that the box of an RV provides strenght to the unit as a whole and reduces the flexure in the frame. It is the flexure that causes failure.