Could look towards doing a "socials" attach to profile, they have on fountain where you can link your Nostr account to it. When initially posting an option to share to associated accounts could be helpful. Would nullify the need for anything to generate a Nostr account for you. You just link yours to SN. If one isn't linked to your profile, perhaps a prompt to the user to say "hey link your Nostr account to share this post there aswell"