I'm a 2017 75 owner as well.
But here's my current understanding, which is somewhat guessing atm. V2 has a Amp limit of ~250A per stall/pair (or 300A max soon). With the 75kWh packs we're limited to 350V, which gives a max power of 90kW (300V * 250A). With V3, looks like they can put ~500A into the car at the same voltage, so ideally we'd potentially see a max of 150 kW charging rate. That's assuming the car can even handle that much amperage, and the voltage of the newer car batteries are still ~400V.
I'm guessing newer S / X have possibly been designed for this amperage but super unknown for older models.