I just did! We had a week booked at YC, but an expensive home repair came up, so I decided to split with Dolphin. I removed 2 days from YC and booked them at Dolphin through Marriott directly. I was able to link the reservation the next morning - FPs stayed put the whole time. However, I made my change within 30 days and we are AP, so I'm not sure how that affects it.
I think the official rule is that as long as you re-book at a resort where you would also have a 60 day FP window, no more than 48 hours after cancelling, you should be ok. And if you use the modify link and just select a different resort, no issues.
