Yes, that is what I meant, but there are two cautions: there is currently no code that restricts which frontend hosts which age. It round-robins, as I said. If
only server B can host a custom hood, the backend won't know when it's doing its round-robin thing. It can be done, but it is not implemented.
On a related note, since ages can move between servers (that is, they can start up on a different server than last time they started up), and some age state is stored in files, you can't have a loose confederation of servers without ages getting reset. The servers need to be able to share files. Unless things are changed for the first caution to pin ages on a given server once they have run there. Or some file-sharing mechanism is built. Or something.
I am waiting for a real live use case with actual requirements that inspires me to implement something more complicated than exists today. Or someone else inspired to implement it.

That would be nifty.
Oh, also, all servers in the cluster have to have the same server-side private keys. There's nothing special about that (and I can guarantee you the MOUL servers are the same on this point, and almost certainly the shared files as well).
But it suddenly sounds to me like you're thinking about a loosely organized system where server Cs are set up by random Joes and joined to the shard with basically no effort. Private keys oughtn't be given out on a whim. And then when Joe doesn't boot his computer today, his visitors will have a real purty black screen.
- a'moaca'