This may sound bonkers, but is there a simple system available that can operate as a very inefficient power sharer from an EV (in an emergency) that involves raising the car off the ground and generating power from running the wheels across rollers etc that then generate electricity that can be fed into the house?
Obviously a lot of energy would be lost in the process, but something is better than nothing in some emergency situations I expect, and this would require no modification of an EV to achieve.
Cybertruck will have (presumably AC) power outlets.
In a major emergency one power outlet can be the difference,
In hot climates keeping the fridge/freezer going..
In cold climates some form of heating and allowing the household to boil water..
For V2G it is probably OK with an LFP chemistry as the cells will be happy to charge to 100% frequently and the car can make some money selling electricity at peak times. That is a lot to set up.
The AC outlet and perhaps some 12V and 48V outlets is cheaper to install and works fine with any battery type. If can be used in emergencies, including topping up a stranded EV driver, but it is also very useful for camping and occasionally for work.
I would probably pay and extra $500 for a car with a AC outlet, because occasionally it will be very handy, and in my case that is keeping the fridge going.
Even with solar + Powerwall, the car battery can be used to run the fridge and lights overnight keeping some charge in the Powerwall so it can help solar to start the next day. Once the sun comes up the Powerwall and solar can generate in Island mode, and that can run the house and perhaps top up the car during the day. Overnight you make the call dependent on how much charge is in the Powerwall, but if I was in a situation where the grid was likely to be out for a week or more, I would run overnight off the car outlet whenever I had the slightest doubt about the Powerwall SOC.
The next great step forward would be the car AC outlet being able charge the Powerwall and provide it with an initial frequency. That could bring a dead Powerwall + Battery system back to life. The technical aspects of this are a bit above my pay grade.