Bluetti already has a product for this available in the EU. I have been posting eveywhere that they need to bring it to the US.

https://www.bluettipower.eu/products/balco-transfer-hub

Balcony solar without storage is actually pretty dumb when we already have integrated battery/inverter/solar mppt units available for a few hundred dollars.

All we need to do is have something like this hub inbetween to ensure grid isolation when an outage occurs.

For crticial loads you would just plug those directly into the all in one battery unit. Almost all of them these day also have a <20ms UPS pass through function as well. When the grid goes down it can isolate the battery from backfeeding the house but the solar will still function and the critical loads will still function.

With a solution like Pila is developing you could even use your homes wiring to transfer power (~1kW) around multiple small battery units (attached to independent circuits) each with some different critical loads and solar attached to them.