I spoke to a CM yesterday and she recommended CALLING to modify the reservation if and when FD is offered. She said that way they can make sure to keep the Gift card on the reservation. Not sure how true it is but thought it was worth noting.
I was told the same thing a few hours ago. The CBR GC offer is being overseen by Guest Relations, so all modifications to a booking with the GC, have to be approved by GR to keep the GC on the booking. The CM I spoke to said the offer was unprecedented in her 15 years of working in Disney bookings, so it's all so uncertain. If you go via the website, any modifications may affect the GC offer. And trying to get them to reinstate it later may be difficult or impossible.
I called to add 2 more nights to my CBR reservation and she had to check with GR if I could keep the GC still!! I was shocked as it never occurred to me that increasing my stay could jeopardise it!
Luckily, GR advised her I wouldn't lose the GC. Phew!
But she advised calling to make ANY modifications so I could be certain the GC was still in place. Even if I wanted to add a (paid) dining package or park tickets to my reservation.
But then again, the CM did tell me that if I wanted to increase my 4 day park ticket while I was there I'd have to do it on my first day of using the ticket as after that I would have to pay for a one day ticket from scratch. Which I'm 99.9% certain is not correct. As long as I upgrade the pass before the end of the 4th day, it will only cost the difference between a 4 day and a 5 day pass.
In terms of my resort booking and fd, I've decided to go online when it drops and secure fd with any mod resort that is roughly the same price as CBR. It may end up being another CBR room even!
And then I'll get on the phone at 7am and see if I can get FD added to my original CBR booking without it jeopardising the GC. If it all goes through, I'll cancel the new booking. If it doesn't, I'll cancel the original CBR booking as we would spend more than $75 (GC amount) on food for the 3 of us per night (we want to do a number of dining experiences). I've crunched the numbers and think I've worked it all out!
BTW, can I just say that it drives me mad that most booking sites in/for the USA don't include taxes in the price. I have been caught out so many times with it! We don't separate taxes and the price in Australia, it's all integrated and by law you have to advertise/display the total price of any item. So what you see is what you pay. I spent ages crunching numbers only to realise that one set had the tax included and the other was missing the 12.5% tax, which put my calculations out by a significant amount. So it was back to the drawing board for me!
I'm learning though. By the time we go in September, I'll have it all down pat.