Wouldn’t batteries for homes and communities be a better target?
Why not both? Sodium batteries may not be ideal for all EVs, but they can be good enough for a significant portion where the energy density disadvantage can be offset, or where the benefits of sodium batteries (such as cost and safety) outweigh it.
Certainly both however the cost of home batteries is very high and anything that can reduce it would be useful. This is especially true of being able to absorb surplus solar energy for use later. Size and weight are not the major issue with static batteries but cost is.