How to set up Actors references to Character?

The question is simple itself. Someone can say “Hey, use public variable”. But it does not suit me.
What I mean. I have child characters. when I do some changes in the master blueprint. all variables comes to 0. It means that all characters for example 20 characters will lose their manually set up variables. My goal is to set referencies somehow in child actor massive before game starts. The other issue is some actors are placed in other streamed level. The Goal character walks from one point to another, it is the same blueprint, so the cast directly to specific blueprint also bad idea. Any help? Data table, or object class, something??