No, it does not. I've had to revise my spreadsheet, because I realized after more research that my hourly rates - peak and offpeak of 0.2c and 0.8c per kwh are only a small part of the actual costs. For the month of July, $86 of my bill was just in delivery charges, which were not factored in at all. That seems to be a way that the utility has of making those off peak charges look really good, when in fact they're not that much better at all.
So I prorated those charges for the two days in my spreadsheet, and added them to the kwh rate - and it's now 12c and 19c per kwh rate. Which means their buyback of my solar at 8c is at worst half what I pay them.
This means that what I thought was true initially still is true - it is better to use my solar and charge the car entirely on that if possible during the day, because it is essentially free. Or not quite - I'll lose up to $50 in credits - but it would cost me $69 in kwh charges from the utility to do the same charging at the 12c rate, and $109 at the peak rate.
So the adding of the delivery cost to the TOU really reduces the value in the difference between peak and offpeak rates (the original difference was approximately 3x greater, now its only about half as much.) And in both cases, it's now clear that a solar charge is going to be cheaper than a utility generated charge, at ANY rate.