zanydroid
Solar Wizard
The XP inverters are not compatible with Gridboss as regular invertersDo you know or did you ever consider combining the FB21 & 12000XP together and configure in parallel? I'm considering mixing these two.
You may be able to look into whether they implemented support for using the XP inverters as generators feeding into either GEN port of a Gridboss or GEN port of an inverter that has a GEN input. I don't believe FB21 has a GEN input.
Also, if you are in the Bay Area the XP inverters aren't compatible with California building code. You're going to have to deal with the planning and consequences of hiding them.