Walking (crawling) on the roof

as a rule of thumb no ladder on back not a walkable roof get plywood dispurse your weight

My manual did not address this, that's why I asked here...

You might want to check your manual first. I thought mine seemed a little iffy.
The manual says not to walk on it.
Put 1/2" plywood on top first to spread the load.
I did sit on the edge and kinda lay on it to put my covers on. It seemed fine.
I'm sure if I stayed right on rafters it would be OK, but I didn't want the old foot thru the ceiling trick.

It probably depends on how heavy you are but they had to walk on it to install the roof in the first place so anyone of normal build should be OK.

I get on mine to clean my solar panels,you will be ok