How to setup Pathfinder data for separated level prefabs

imagine that I have 100 prefabs and each of them represents a room in a integral dungeon.
The dungeon will be generated procedually during runtime, and I want to save the GridGraph data to each room prefab at editor time.
What’s the best practice to do it?

How many Pathfinder components are allowed to be existant in a same unity scene at same time? only one?
How many GridGraph I could create in a Pathfinder component? I saw it only support 32 at most.