I love the deck!!! My bus is already just a hair under 40', but I am going to seriously consider doing something like that in the future. Also, I love the solar stuff, nothing like lots of shiny new expensive electronics
I used to extrude composite decking, was actually the lead extruder operator. Example of what would be a problem...if decking was installed at 30*f, 80*f would create large bows. If it was installed at 70*f, and not supported like yours is, 80-90*f in the sun
would create large bows. Also, the darker the color the worse the problem. One trick is to predrill the decking enough that the screw has a fair amount of slop (up to 1/16" oversize) in the board it is passing through. That gives it room to flex before it starts to bow.
Seriously, the way you have that supported I highly doubt you will have any issues.