Of course, that's why I mentioned it. The Powerwalls allow me to only draw Off-Peak energy from PG&E for 6 months a year. There are probably another 2 months a year that I draw some Part-Peak but nothing during Peak. The 4 Winter months, I don't have enough solar generation to even cover my Peak usage.
Yeah, that's why the dream is to be able to grid-charge your Powerwalls a bit using off-peak energy at like 1am. Then when the next day rolls around, you get some solar production, and the Powerwalls fill up enough to bridge you through the shoulder/peak time. This is especially useful if there is a lot of cloud cover or weather further dampening solar production in that Winter month.
I really don't know why Tesla will not allow this type of programming. It helps lessen the load during peak time and presumably wouldn't significantly increase the dependence on fossil fuels or imports compared to the homeowner not grid-charging their Powerwalls.