My idea is to have something that plebs can use to batch transactions. I floated it here.

Well, nostr is actually not a strong requirement for this. But it could be a nice to leverage all the network effects it already has. Maybe something like NIP-28 could be used to post PSBTs in a public channel.

The main objective here is just to shave this 5 to 7% tx overhead, not so much gain in privacy. But some privacy might be gained, depending on the amounts involved. Plus we screw even more Chainalysis' common input heuristic.

Also note that 5% overhead can sound as very little, but not if you're seeing 300 sats/vbyte right?