If that's a rubber roof, you really don't want to use a pressure washer on it anyway.. Regardless of the sealant used or the surface cracks on it..
Would you put your hand under a pressure washer nozzle? The thin rubber isn't much stronger than your skin, except it'll handle UV rays a lot better..
๐All I do with my rubber roof is get up there with some car wash soap, water and a soft scrub brush that I use to wash all my other vehicles, to clean off the surface dirt on the roof and be done..
Been doing that since 2003 with mine. I wouldn't even think of using my pressure washer on it..
Good luck with whatever you decide to do.
What I don't like with that "caulk" job is all the "pools" it makes between the joints, but I guess there is not much you can do about that now?
Mitch
2013 F150 XLT 4x4 SuperCab Max Tow Egoboost 3.73 gears #7700 GVWR #1920 payload. 2019 Rockwood Mini Lite 2511S.