Can a double conversion UPS energize grid-tied micro inverter solar array during power outage?
I think the odds of that working are very slim.
The UPS is much smaller than the inverters, so it will struggle to maintain a stable 208V 60Hz.  That's especially true if it's not intended to be back-fed.
It will be very difficult to get the load to exactly match the generation.  Too much load, and the UPS will shut down, followed immediately after by the inverters.  To little load, and the inverters will attempt to push out current into no load.