Are there any downsides to speak of when using a Blueprint Interface vs. casting to a known class and calling one of it’s functions ?
Theres not much difference in cons and pros, rether you need to understand what are they for
-Casting is for accessing functions of child class in parent class object reference (parent object from variable , return)
-Interface is for using 2 unrelated classes that can do same action (set of function), so you attach them to same interface and it can be used in same argument for example.
Soin short if you dealing with related classes use casting, if unrelated use intefaces