Something to be aware of, and this is still in flux as the market is so new, but when sodium-ion batteries that use Prussian Blue/Prussian white cathodes enter thermal-runaway (or catch fire for whatever other reason), they release hydrogen cyanide gas.

Obviously manufacturers are aware of this and other chemistries of sodium-ion exist, but when a market is new you can sometimes get all manner of competing tech floating around.

I have entertained the idea of being an early adopter for home battery storage, but learning this made me hold off until their was more info/you could be sure about what you were buying.