Rice, very good points.
I have been surprised as well at "professional" installations that leave you scratching your head. Before buying any panels I took measurements of the trailer roof and all obstructions. I used a free CAD program to draw it out. Then looked at various sized panels to see what seemed to fit the best and bang for the buck. Even deciding how far out to install them away from the vent cover vs. how near the edge of the camper had to be somewhat balanced out. I was afraid mounting them too close to the edge might incur more risk of damage from branches. I probably over think things too much.
I ended up making my own brackets which sit a little higher than normal so I could clear one bathroom vent. That raised them a little more than some which also helps just a bit with shadows. The brackets would give me the ability if ever needed to tilt them (doubt I will) and get access under them if needed.
For sure shadows can be a bad thing, especially if you are close on solar sizing.
I hope anyone that comes across this and is looking at building their own system or even having one installed by someone else will take the time to read through the links I included for some very good reference information. There seems to be a lot of installations that aren't done well and under-perform for various reasons.
This was a fun project and I'm looking forward to seeing the results of it.
I still have some more lights to trade out for LED's and I want to install a couple more 12v outlets then eventually a medium sized inverter. Bur for now I spent enough :)