[stevehull]

I have no problems mounting the junction box under a panel. That is what I did to protect it and to provide easy access through the roof.

Voltage rise is not all or none. It is progressive and the mid string minimizes the voltage rise. I even use a mid string then I only have a 8 panel string (4 panels on each side). The efficiency rise is small, but multiplied over years, and with modules, it really adds up.

I hate conduit on a roof - metal or PVC. In your case, it will only be partially visible, but it looks REALLY ugly. It also gets uglier as you look at it longer. Yes, if you do mount conduit on the rood you need have have PVC stand offs - which require drilling through the roof . . .

So I prefer to go straight through the roof, from the bottom of the junction box, with PVC. Then I run PVC conduit inside the structure where it is protected from UV. The electric type gray PVC is resistant to UV, but it is not impervious.

I mount a 3/4 inch PVC screw type male onto the bottom of the plastic 6x6x4 junction box. That connects to the plastic conduit.

With your beautiful roof, I would not use surface mount conduit. Yes, this means holes through the roof, but when protected by the panel, and well caulked, it is just not an issue.