roastr brings a threshold multi-sig option to nostr by leveraging FROST/ROAST. (Fedimint's tech enables this because of the consensus mechanism of Fedimint coupled with FROSTs nonce management requirement.)

you can create a nostr account that requires 2of3 or 3of5 or 1of4 signatures to be valid. This means that a multi-person entity can have a quorum of signers for nostr events.

you can have a nostr account with friends. where you can "vote" on approving a note (or other stuff). Enterprises can have a board "vote" using nostr.