I can't wrap my head around what off-grid balcony solar even means. Balcony solar is meant for apartment dwellers. Or detached home/townhome owners who don't want to spend on a rooftop install. You aren't installing balcony solar to go fully off-grid.

Sure, but you don't need to go fully off-grid to have an off-grid balcony solar panel. You can connect it to just your freezer, or just a storage heater, or to the batteries you run your homelab off of.