Partial Merit Removals make no sense and should be removed.

[kayabaNerve]

If the first Element isn't known, as the peer has yet to sync its Block, the PMR will be rejected. If the first Element is known, sending the second Element alone would be enough to trigger the PMR. If the first Element isn't known, the second Element alone may still be accepted instead of rejected, increasing the chances the peer will eventually create the MR.