As I understand it, on a modern RV, It is generally considered that if you don't have a factory ladder, you should not walk on the roof.
These days the RVs are made with such light materials, that it just isn't advised.
I know my roof is very light, and I have leaned on it and it gave so much that I would never consider walking on it.
I put new Maxxair fans in both the vent openings in mine and did fine with a 1/2 sheet of plywood laid down for support.
I see yours is the 'Lite'.. I'd advise against it.
Doug and Patience and Shelby the mutt
2015 Crossroads Sunset Trail Reserve ST26RB
2013 Ford F-150 3.5 EcoBoost XLT Supercab 4x4