Well, for those waiting for their 'I thought it was too good to be true' moment this is it. the 3-in-1 solar converter did not work out. I connected the PV, and the box made some unsavory noises, and then turned into a short circuit. no idea what happened, other than error code 9 on the LCD, but the array had 311vdc and when I close the breaker it goes to 2.5VDC, just like a short. its not to ground, PV+ and PV- are shorted.
So I found a different way to do it, significantly more expensive though. instead of a 3-in-1 unit I'll try to get higher feature-content individual parts. most importantly, I have a epever 200 VDC, 100a MPPT 48v charger coming, which has a generator start and inverter load function. Since the solar input voltage is much less I'll need to break the solar array into 4S-4P panel arrangement instead of 8s2p, I'll just need to add a few more feet of PV wire and terminate some extra MC4s, no big deal.
the battery is taking shape, my 32700 cell endcaps are on thingaverse. https://www.thingiverse.com/thing:3691963