https://hzrd149.github.io/applesauce/overview/relays.html#updating-filters

This allows clients create a subscription before the filters are ready and update it based on some other value that is changing ( users contacts or pubkey maybe )

Thanks to nostr:npub18vay956v7zs5qtgc65mvn54v96cuvqv6j9fmu4cgfjqkt5vjuvjsc47nzf for giving me the idea :)