We are literally talking about trickle charging!

Tesla is notoriously conservative about charging at L1 speed on a cold pack. Most other manufacturers will divert a lot less power to heating the pack. I’ve never had any issue charging at L1 on the 3 EVs I’ve owned in Chicago (all non-Teslas, and non-Fords either). I know some Tesla drivers in Canada report that their cars will use the full 1.2kW for battery heating and zero energy actually goes into the pack. This seems overly conservative to me. But Tesla knows best, I assume.

Insteon and x10 both did this. There just aren’t enough benefits.

I have like 70 Lutron Caseta devices in my home (in a congested city with a UniFi WiFi system (4 APs) and a zigbee and a zwave network) and they’ve literally never once dropped a single command signal. Ever.

I think wireless congestion can be an issue for sure, but clearly there are ways to engineer around it that don’t involve powerline. Powerline brings too many of its own issues (latency, and poor signal reliability come to mind).