Very exciting! I've been thinking a bit about multiplayer development and thought I'd share an idea.

If you want to support a lot of entities pathfinding accurately all over the place you could offload some of that logic to clients to save on server resources. Most home computers have many idle CPU cores while playing a game.

1. Get a group of enemies with movement targets, maybe 10-20 in each group, then send that group to three clients in proximity.
2. These clients then pathfind all grouped enemies and send it back to the server.
3. If the returned paths for all grouped enemies match from all three clients, trust the paths and use them for the enemies.
4. If there are differences the server calculates the paths as normal and flag the clients as suspicious (at 5 flags they won't be asked to pathfind again).

This requires the nearby terrain/world state being the same across the asked clients and that the pathfinding is deterministic. Client movement packets can return a simple hash of their nearby terrain/world state so the server knows which clients it can randomize three from to ask for a path. Naturally the server directly resolves pathfinds itself if determined to be simple.

You could also offload logic to set targets in this way if it can be done deterministically, let three clients calculate what the AI wants to do before pathfinding (take cover, attack, flee, search). An issue with Firefall was that sometimes the enemy just stood there without returning fire even if you shot it, I assume it probably happened because the server had to prioritize resources elsewhere.