setting aside the whole IRS piece for the moment, I wonder how often this will come up. In the Mach-E side we saw this occasionally - where apparently a person was legitimately going to buy the car for their own use and then due to the long delay and life circumstances, they couldn't actually afford it when it showed up (and knew that before it showed up). I think especially with the high end on the Lightning, where a bottom line of over $90K is in play (which is the case stated here), it's going to come up, but it will be interesting to see how people deal with it.
Ford restricting the transfer of the reservation is very reasonable in some ways, but it does have downsides as well. For the OP, the best outcome I'd think would just be to be allowed to do a "zero cost" transfer to a willing buyer, which there are plenty of. But that's not a real option so...
I suspect someone reading the forum will be willing to make the purchase from the OP but if it were me doing so, I'd do it in PMs. No reason to do it all in public.