we had some softness about 2'to 3' in from the door. its a 2010 I believe and in mint condition, been stored in a heated shop most all of its life. so I was surprised and got to checking I could feel it just a little when I walked in i'm 170 but my B/L is 270+ and he could really feel it. I couldn't find any soft wood even taping with a hammer the wood sounded solid. I then had my B/L walk inside wile I laid under the t/t and I could see the floor move and the reason it was doing so. the soft spot was right in the middle of the frame bracing it was nearly 3' each way to the nearest support. the fix was I welded some intermediate bracing in that area and that cured the problem.
Jay D.