Currently all ghost prefabs will be evaluated by netcode system and it will be quite expensive if u have huge amount of ghost prefabs. I would like netcode support EntityPrefabReference from entities content management that by default all ghost prefabs are not loaded at both client and server. When server load and instantiate a ghost prefab dynamically, it will automatically inform all clients to load and instantiate that ghost prefab dynamically too. So basically now it’s load by demand to reduce the performance stress of processing all the ghost prefabs even 99% of them are not used. And also for most cases u dun want to ghost entity to spawn late, official can implement a built in rpc for this to inform client that all the ghost prefabs needs to load beforehand. Basically how it works is you load ghost prefab at server first then just create this rpc entity to inform client to load the same set of ghost prefabs as server. For people that dun care about this still can just assign all ghost prefabs and it will still work like before.
Currently netcode is too strict that when server spawn a ghost and client does not loaded that ghost prefab yet, it will just throw error and the game will stop working. This strict limit needs to be removed first to enable the feature I mentioned above and open more possiblity.