What I've been told is that once you receive a DORA, you have 1-2 weeks to make changes. But when a VIN is produced the order is locked in and cannot be changed.
As for your deposit, I believe that is dealer specific. I placed a deposit on a Raptor all the way back on January 4th this year, targeting a 2019. My dealer said the deposit was refundable as long as no order was placed. If an order was placed and not fulfilled, the deposit could be transferred to another vehicle. If the deposit was placed, the order fulfilled, but delivery was not taken, it would depend on the order whether they would transfer the deposit to another vehicle.
I would call dealer 1 and inquire about getting your deposit back before submitting a second deposit with dealer 2.
Not entirely correct as the dealer I ordered from had a VIN and scheduled date but they were able to change almost everything, color, seats, other options. It’s just that only 2-3 changes can be done each 24 hrs. So if you have a lot to change then it will be a few days before you get your final DORA. We were even able to get drop shipment to a local dealer 2 weeks before scheduled date.
I guess anything is possible as long as your dealer is willing to take the time and effort.