Just spoke with Ford Financial. For a lease, the payoff goes to the originating dealer (or another ford dealer if the original isn’t available). This is whether I buy it or trade it. They didn’t seem to care whether it was traded or not, just that the full payment be made through the dealer to end the lease (contradicting what the dealer said).
They said outside of 120-days, the third-party buyout price is the same as “my” price, which is the end lease value plus the 500 fee for “buying” out the lease.