I wonder. Couldn't soft spots be fixed by drilling a hole in the floor, clearing out some of the foam, and then pouring epoxy in? That is how you fix soft spots on a boat that has the balsa wood rotting between the exterior and interior fiberglass.
2016 Jayco White Hawk 32DSBH pulled by 2014 Chevy
Gone-2013 Keystone Bullet 294BHS
Gone-2007 National SurfSide 34DE
Gone-2006 ForestRiver Sunseeker 2900LTD
Gone-1994 Fleetwood PaceArrow
Gone-1978 Kit RoadRanger