Originally Posted by bluecrab
I take delivery of my 2021 Flagstaff 21FBRS next month, so I will check this.
My 2020 Rockwood Mini-Lite has the upgrade. Your 2021 is certain to.
I had the underbelly off for other repairs. The supports are definitely better than were on my 2014 Flagstaff hybrid. In addition to there being three supports rather than two, the front-to-back supports have bolts through the ends. That keeps the tangs from pulling out of the slots in the side-to-side frame members.
I filled the 60 gallon tank completely. It bellied out slightly but not much. I would be confident traveling with it full if required. It worked fine on a recent 70 mile test drive. (It put my trailer slightly over its GVWR, but that's a different issue.)