I'd go with fixed mount on the davits
. It would also be easy to clean them and provide a bit of shelter to your dinghy
Usually as far aft and as high as possible is the best place.
Most mid size catamarans mount them either on a hard bimini
or over their davits.
Re, movable panels, I'm always amazed when I see a cruiser anchored, drifting around in circles in light wind
readjusting their solar panels
every few minutes. They look like slaves to their panels...
Imho, mounted flat, with more panel area is the best way.