Manual tracking scales poorly. Instead, by placing Treasury funds into Optimistic Vesting Vaults, we allow scheduled payments to flow automatically unless challenged.
This is how it works already. Proposers can schedule many payouts via a single referendum. If those payouts are not canceled, they will flow automatically. Here is an example: https://polkadot.subsquare.io/referenda/1794
Also more reading on the topic here: Treasury Guardianship
Your zk stuff sounds interesting but since anyone keen on staying anonymous can just create a new wallet and any wallet can create a delay/cancel payout referendum, I wonder if it is really necessary?