I replied to his "federated" Threads post this morning:
"@pcottle
I see the clone of your original post from #Threads on my #Mastodon instance
Do you see my reply to your original post from Threads back over on Threads?
Betting you don't
Replies to Threads posts (those selected few that are allowed to clone their posts to Mastodon) never propagate back over to the original on Threads"
At 5:05 pm PDT he still hasn't seen it or replied, and my reply hasn't propagated back over to his original post on Threads