Well I finally moved the trailer out of the shade today and the performance was very good. Peak wattage into the batteries was 377.5 out of 400. This is 93% and the best curve for my MPPT controllers was 96% so I'm pretty happy with my configuration and monitoring. The only fly in the ointment is that I though I read these inexpensive meters would roll over at around 6kw but they roll over at precisely 660w... which explains some mixed results I'd been seeing.
This means I won't be able to use them to track my daily wattage unless I keep track of how many times it rolls over in a day. That means I need to babysit it. I'm predicting it will roll over at least 2 times a day under ideal conditions, maybe even 3. I need a day when I can sit around and enjoy the trailer and maybe a few Margarita's to boot.