Quick novice q - I'm mounting my panels on my box corrugated roof and tilting them on struts to be the optimal angle. They will be in landscape mode. As they are less high, and as they are attached by hinged feet at the bottom, do I still need two rails across them, or will just the one do near the top where the struts will attach? And if only one rail, would you bolt a flat aluminium plate between the panels just for slightly increased rigidity, or leave the feet to do the work? Panels have the usual 30mm all frame round them and appear reasonably stiff, but it's not overly thick alu, obviously.