I think @codinghorror has been quite a fan of using PMs for long drafts, having it block yourself is not our intention here:
There is a very simple fix/change in Discourse:
Swap to:
def unique_post_key
"unique-post-#{user_id}:topic?.private_message?:#{raw_hash}"
end
That plus a quick test will fix this workflow.
I do not thing safety guarantees are hampered by this change.
Will go ahead and make this change tomorrow unless there is an objection.