I decided to test immediately and agree if I set the sync_id everything works perfectly.
For your interest, I decided to keep the original tasks created_on and set changed_ts to ~now, as expected I had to push from clientA but I’m happy for this to be a once off so I know how long things have been pending. ClientB and Server can modify tasks and they’re correctly replicated so I’m very happy.
Thanks for the help! You may want to update JSON Data Format | Everdo Help if you don’t get time to amend the import code soon.