[Retric]

I think the OP was just confusing a feature used by someone with a Tesla from a Tesla specific feature.

They might be using one of these: https://www.chargedfuture.com/240v-outlet-smart-splitter/

There’s also smart breaker boxes that again have nothing to do with Tesla specifically. The breaker box will preferentially shed EV charging first when someone would otherwise trip their whole homes’s connection to the grid. It’s not a perfect solution, but sometimes your local utility doesn’t want to upgrade your connection to the grid because their substation is fully provisioned or whatnot.