As I posted in another thread here, normally it should be okay to run a scripting VM (like Blueprint) because most games are bottlenecked by the GPU rather than the CPU from what I’ve seen on PC, etc.
So, I am not sure what your objective is in asking this question. Also, as a rule of thumb, optimize when you need to (not before). I wouldn’t worry about Blueprints over much unless it pops up on the profiles. Then you gradually move those expensive routines into C++. I personally haven’t had any issues with blueprints but my project is in the infant stages