Solar Branch Connector OK under panel or exposed?

I did just as you are proposing...all connectors and a loop of excess wire tie-wrapped up under the panel. Easy enough to pull out for inspection and maintenance plus connectors are out of the elements as much as possible.

Daryll

not if your using 'solar wire' or other out door weather rated wire

Can the heat ruin the wire or worse the roof? Mine has a 1 1/2" air gap.

Tucked under the panel is ok
Just remember to clean out the leaves and debris
A couple of times a year
Mine are wired up that way, with extra slack wire under the panels

So long as the wire is not going to be flapping around in the wind as you drive, I don't think it really matters where it is located. Whatever seems tidier and gives the most flexibility for maintenance or repair if needed would be my choice. Cutting the wires to the proper length is also a good option (assuming you can make proper terminations on at least one end of them--which isn't too hard if you're going to a screw terminal or wire nut or something of that ilk).

Any connection is a potential weak point. Make them accessible one way or the other. I have had an MC4 connector break for no reason.