C++ and blueprints! Communication and performance

Hey guys I’m a blueprinter but I would like to start moving part of my game to c++ for many reasons. I watched this for some optimization tips ( ) and I decided to start now.

In particular I would like to avoid Cast (this guy says with c++ events you don’t need to cast, but I know I could use bp interfaces too) in order to load only the content I need and Save and Load game via C++. My question is, would make sense if I save/load for example my game in C++ and then call this specific action via blueprint (so all my game flow will be in blueprints)? Or should I do this only in C++? I know it may be a stupid question thanks a lot for your help guys!!!