@Stella.Q Thanks, I'm aware. The first sentence mentions the neutral only for context. The question is after that. I'm looking for a switch that looks like the kasa switch, and has similar physical...

In my hallway I have a 3-way circuit where the second junction box only has two travellers, a line (common), and no neutral. Using the second HS210 there from a 2-pack is apparently not an option....