Just so you know....
We had a 5:00 opening reservation for Spoodles before Fantasmic. It was rather rushed to get back in time to get seats for Fantasmic - we ended up taking a cab and didn't order dessert.
It works, but unless Fantasmic is showing late, you'll want to book an hour of travel time (half an hour each way) and be prepared to rush.
Unless there is a late showing of Fantasmic, I wouldn't recommend FF, which will be much slower.