I'm not really looking for a backup and isolating critical loads, only daily and regular cycling to even out my peaks and valleys while reducing costs of buying power back. All I'd like to do is to reroute some of my solar overproduction from the main to the 10 kWh+ batteries and releasing it back (replacing or supplementing power from the grid) to the main at close enough and specified rates to be consumed in real time (usually at night, peak TOU, or when charging my EV.)
The main reason is that my net metering sucks, pays 4 cents/kWh, while what I buy costs me anywhere between 12 and 30 cents.
EDIT: El cheapo idea I had was to plug into the 120 V outlet and remotely trigger my existing 48V Delta-Q charger to charge the battery bank in the 48 V configuration. An inverter of some kind is then needed to release that energy later, therefore, the discussion around the Chinese grid tied inverters and much more expensive AIMS that are nice on paper but unreliable with only 1-year warranty.