I thought there was an option to revoke or reissue by including oneself as a recipient?
I see what you mean though about a unit transaction…
I get it. spent. semantics. From a practical point of view I don’t see why anyone would create an offline dbc they did not have the ability to revoke and reissue should the intended counterparty change. The same might be true for some online transactions too. It doesn’t feel like a “spent” until the dbc has been physically transferred and reissued by the recipient to not include the original owner.