I like the bootstrap archive notion. We can keep it out of the general relays. I’m mostly interested in content creators who have invested major effort and would be willing to go an extra mile to set this up on a self-hosted or paid relay. I don’t expect it to work with zero input from the user.

For the clients, maybe they can offload the task to a DVM so they don’t independently have to implement the same lookups. The DVM provider can also supply the archive and then use it to inform the clients on demand.