Good question Hank.
Two years ago a friend converted a "skoolie" (school bus) to an RV. He used the Sikaflex 252 to glue his panel mounts to the painted roof. He tested beforehand to ensure the 252 had no bad effect on the paint. He used 2" angle aluminum stock . That was 2 years, thousands of miles with 70 mph speeds plus winds and all 10 panels are still well affixed to his roof.
So I tried scrapping the roof sealant I had applied. It was well adhered, but could be scrapped with a good paint scrapper. Therefore I did a 50/50. I marked the positions of the mounts and scrapped away strips of paint. Then laid the Sikaflex over painted and non painted surface. The mounts were screwed to the panels and the whole thing pressed into place. First the forward panel, then the rear one.
The charge controller behaved as it should yesterday. After being in absorb for the preset 2 hour time it switched to float at 3:30 PM. I then tried a manual equalization charge. That is another 2 hour timed event. At the end of the EQ it went back into float and stayed there until the sun got low enough to quit. I then started the fridge and let it run overnight. This morning when I got up (7 AM) the charge controller was already awake and in bulk. No direct sun at that time so it was only 0.95 amp. But it works.