Of the FTC, KC AG, and KC BBB, the KC BBB was the only organization (so far) to actually service my complaint.

Sadly, today they administratively closed my complaint, citing that they had made a good faith effort to resolve the complaint.  So I called them up, and spoke with the person assigned to my case (Lauren) and she told me that the BBB's investigator had decided that BFL was not doing anything wrong, and that they were going to wait until after September 30 to take further action.  I didn't understand why this was the case, and didn't get a very detailed answer when I asked, other than that September 30 was given to the BBB by BFL.  My first piece of correspondence with BFL through the BBB included that date as well, as the current estimate for most of the backlog to be fulfilled.  But that was the first I'd heard that date.

So I have an open question to the investigator about why BFL is considered to have done everything above board when they didn't give definite shipping dates, and also didn't give another chance to receive a refund after failing to meet "two months" after May 1 (when orders were reconfirmed for the chassis change).

I guess I'll wait for the investigator's reply, but it seems like based on the BBB's response, the AG is the next step.