set In-Reply-To and References headers in MDNs?

[r10s]

shall "Read receipts" aka "MDNs" also set the In-Reply-To and References header? referring the message that was actually read?

currently, this is not the case, however, it makes some sense to avoid unsorted, unthreaded messages in the INBOX folder (or whatever folder is used).

otoh, these messages may disturb the thread as such, so i am not really sure about this point.

in the near future, other report messages (syncing ...) may be added, so maybe the MDNs are not really a huge problem ;) the best would be if the other MUAs would not show them so prominently ...

[testbird]

They may all get only a common (static) References header to at least bulk them away to the oldest message.