Hi Martin Booth
Thanks for reaching out, sorry about the issues you are having, I hope I can help clear up a few things. The new change to update the existing task is not a something that is handled by the Power Automate connector. As you pointed out there are no output parameters from the connector because it only acts as a scheduler. Based on the flow, the connector will run on a certain cadence, when that happens it makes a single call to the Admin Center letting it know that the Admin Center should run the sync process. The Admin Center does the rest of the work and handles the sync between Planner and Message Center.
I did talk our devs about what kind of information we could send back to the connector but I do not believe we would be able to provide you with the information you are looking for in this instance.
What we are currently looking into at the moment is different ways to identify the updates as we have heard the feedback that it is not easy to tell when an task is updated. Ideally what kind of way would you like to see when identifying tasks that are updated, via tag/label in Planner? Moving to a difference dedicated bucket? Please let us know so it can help us shape the product direction.
Thanks,
-Paolo