I can not vouch for your roof but i can safely walk on mine without any further support. You may find it hard to find enough space to put plywood on the roof to begin with, let alone it being heavy and having sharp edges. A good alternative would be to use 2" thick rigid foam insulation board (usually pink or blue). It will help spread out your weight among a wider area, as well as being light weight, easy to cut, and soft on the edges so it won't damage your roof. you can get it in 2x8 foot pieces that will be easy to cut to 2 smaller pieces that you can easily leap frog to get around your entire roof.
Travel Trailer: 2004 Flagstaff 25LB
New Tow Vehicle: 2017 F-150 3.5 Ecoboost, supercrew short bed FX4 Lariat
Old Tow Vehicle: 2009 Silverado 2500HD 4x4 Ext. Cab Short Bed
Travel Pooch:Sophie the Sato - Cats: Rhody and Hazy
2018:22nights / 2019:31Nights / 2020:15Nights