I don't know where you are

Germany, 3-phase, 400V to the home is pretty much the standard here.

We use split-phase, where we have two 120v lines that use a common neutral

Yeah, yeah, I know. It was frustrating in the beginning of electric cars - all the manufacturers put those single phase chargers into their cars because US and Asia just didn't need anything else and we were left bumbling along at 4.2kW charging to avoid too much asymmetric load (most providers here limit you to 20A asymmetry although I've been known not to give a fuck) while two wonderfully capable phases sat around doing nothing and the third was only used half the way at most.

This is really where smart appliances should be heading.

Yeah, that looks interesting, although it's unusual to see any "intelligence" delegated to the panel housing. Usually here, the panel cabinet is something like this:

https://files.catbox.moe/qjmpal.png

...which is a mechanical housing and some very basic distribution on the lower left. Everything else is built while the distributor is fitted. Look like this in the end:

https://files.catbox.moe/7u8yzm.jpg

Anyway, you can get this functionality right now, for example with a go-e wallbox and the go-e controller and retrofit it without touching the rest. That's not really a reason not to get an electric car.