I'll check out that website, thanks!

Detached garage would add about 250' total to the plumbing (about as much as putting the panels on the west side) with the additional pain of tearing up concrete to get plumbing routed.

I can fit 6 panels on the NE roof and have no issues with drainback or rubbing.

Or I can fit 7 panels on the flat roof but have potential issues with both.

I guess some panels facing a non-optimum way is better than none at all?