the exit is namecoin (or any purpose-built chain). nostr can plug straight into it — amethyst does nip-05 verification against namecoin now — search mstrofnone.bit and it resolves. you can browse the verified mappings here: http://6cbn4rskfdr647otej7gpqlmpqcmj723vg2eoeuu7ljbwu6cpdebozyd.onion:8080/