NPC’s should be spawned by the Game Mode. When it does spawn them you can in fact set data on the class. For example you can have a single variable in the parent class… NPC_ID (Name type). The NPC_ID would be a row name from a data table. You can set this to be Rep Notify.
So GM Spawns Actor from Class → Return Value → Set NPC_ID.
The Onrep function in the class uses the value to get the data table row, set vars in the class, call whatever functions etc. Easy Peasy.