Yes, you can use any food court on property that you want. That being said, unless you are at that resort to take a break from a close-by park, it’s not worth the travel time unless you are driving around WDW instead of taking the buses. Even then, the other food courts really aren’t that special unless your family has a favorite they must do. the food courts more or less offer the same kinds of stuff at each resort. Sure some of them have specialities specific to that resort, but CSR has some serious variety.