Some year ago (maybe 2016, I don’t remember anymore)
I built a tool to do this, transfer variables between many unrelated blueprints of any class without making them parents of each other.
But, it doesn’t have a GUI and if you don’t know C++ it’s dangerous to use…
I will search to find in which HDD the codes for that thing is… If I find it, I will see this weekend how hard would be to make a Editor Plugin with UI, that would allow for any developer to use it safely 