This is completely divorced from what I wrote. The point is that assuming you can simply take capacity in EV batteries, and use it as part of your grid storage

This is completely divorced from what I wrote. The point is that assuming you can simply take capacity in EV batteries, and use it as part of your grid storage is absurd and uneconomical. Again: I'm not selling you cycles on my battery because they cost more to provide then the electricity is worth. The idea that I might modify my charging behavior based on price is quite separate. The point is you don't have electric vehicle capacity available to run the grid - you have disconnectable loads at best. And they're not that disconnectable: after all, if all cars are electric, then all logistics is electric, and a huge amount of that is no longer optional load - it needs to run day in, day out.