Whatever dude. You can do whatever you want. If you want to overbuild and overpay, be my guest.
My whole point is that 9.6kW is plenty for anyone not running a taxi service and a 14-50 (or 6-50) is THE most universal way to access that power. That is a dead to full Model S/X in 10 hours. 3/Y in what, 8 hours?
I truly do not get this obsession with charging at ridiculous rates at home. You are literally just wasting money. More current creates more heat so the car has to spend more energy cooling itself so less goes into the battery. Idk if anyone did the test w/ the modern cars, but in the Roadster days, Tom Saxton determined that 240V/32A was the most efficient - above or below that a smaller percentage of power from the wall actually went into the battery. Was it a lot? Not really, but unless you are on the road, you have all night to charge. Why be in a hurry?