I have been told the exact same thing about the .00005 cap by a dealer in PA and believe it to be accurate. I also understand that with Audi, the first MSD does not count toward actually reducing the MF…it’s only upon the second MSD that the MF begins to adjust. I ended up doing a deal on a $52,215 MSRP Q5 P+ and landed at monthly of $594; $2600 in MSDs, taxes rolled in, and only the MSDs plus doc fees and first month due at signing. Q5s are not leasing great in the north east/mid Atlantic right now from what I can tell.
As far as trading that 06 Accord, your best bet at getting a fair price would be selling through a Craigslist ad. I can’t see a dealer (or vroom, carvana) offering much on that car, but I just sold our 06 Accord via Craigslist in March for $4,500. It had 144,000 miles and was a 6-speed manual.