Well here is the follow up. I sent an email to the manufacturer asking whether I could walk on the roof. The manufacturer requested the VIN to check their records. They came back as said not to walk on the roof.
I mention to them that the manual said to check the air conditioning which would require walking on the roof. I suggested laying down a plywood sheet.
The manufacturer suggested I use the old cement finisher’s trick of two pieces of plywood.
I have an old sheet of plywood that I could cut in half and use two 4’x4’ pieces; although some recommended 3’x3’ might be handier.
At this point which ever size I use, I am going to keep my “roof time” to a minimum.