I believe you are mis-informed. The Tesla Powerwall 2.0 with integrated inverter does not use a pack voltage anywhere near vehicle pack voltages. I believe it is less than 60VDC like most other battery inverters so that it can avoid special regulatory requirements for HVDC.The DC/AC inverter to do V2H is already within the PowerWall. It wouldn't be too hard to just take the battery source out of Powerwall and make it a stand alone "connector" to the car - an HPWC-2H.
Powerwall uses a high voltage battery set and presumably high enough that it "mimics" the voltage in the car, so it would be assumed that this isn't too hard to do. Mix in the SolarEdge PV inverters and you have V2H done well. By making your car a "PowerFloor" or whatever you could call it, it becomes more valuable. A used Tesla at $35k now is worth roughly $40k to 45k because it replaces a powerwall or a Generac generator in function. if you have a vacation home and a regular home, you could install the adapter in both locations allowing for standby power wherever you are. I don't see why people have a problem understanding this value-add a V2H offers. Probably because the grid is so-very reliable. The fear pushers who want to "get off the grid" are missing the point of the largest machine in the world - the national power grids of North America that are near 99.99% uptime to all locations, save for things like PG&E wiring-induced fires or lightning storm issues.