It’s a little picky, you have to have the BP open and selected and you’ll get a menu where to save the H and CPP files. Only crash i’ve seen is on really large BPs. If you don’t see menu you don’t have proper context selected to invoke it.
Im not sure how supported it is as BP are converted to a VM bytecode and interpreted from what i understand. (Just select some Nodes, Ctrl+C and than ctrl+v into a text editor to see bytecodes). Either way you’ll see what C++ functions are being called.