You can absolutely pass structs in a reference…
There’s nothing (that comes to mind right away) that you CAN’T pass as a reference… A reference is just a reference, there’s no limit in Blueprints to what you can reference…
I use references to structs quite a bit in the game I’m currently working on. In fact it’s extremely common with systems like inventory management. You have to get a struct from the item being dragged, dropped etc…
You CAN do it in Blueprints. In fact there’s multiple ways to do this. Message me and I can give you a few ways to do what you’re trying to do.