Is there a reason you wouldn't use a tangzhong or water/milk roux in more desserts like cakes?

Coconut cake is a pretty common dessert in my family for holidays/special occassions, but more often than not it's a bit dry and stiff, I'm hoping that this thanksgiving I can make one that requires a bit less work to swallow.

Edit: I know it's more common in breads like dinner rolls, but I haven't seen it in many other use cases