Is there a way currently to transfer server world cache between different installations/machines?

If not it is definitely a feature I'd like to see, especially for popular servers where this mod is useful like Wynncraft.

But there is no server world cache? (assuming you mean a client-side cache of the server world, which you seem to be implying)

FarPlaneTwo needs to be installed on the server too

This could be asking about transferring the server fp2 cache to other servers, which can be done by just copying the fp2 folder over.