interesting, i hadn’t considered this angle! i was too focused on the bit where it preserves privacy in deliveries to notice that it also has the benefit of allowing multiple delivery.
my only concern is that it might make error signaling more difficult, because you’d need to be more specific about which part of the delivery failed (expressed as combinations of object activities and target inboxes? like “delivering activity 1 failed to inboxes b and c, activity 2 failed to inbox a, and activity 3 also failed inbox a”). but error signaling is still not defined or used anywhere so there’s room to work out something more robust than just sending a single Reject