Challenge maintainance workflow

I have been looking throught the UI and the API docs, but can't figure out how I am supposed to manage challenges. I have created a challenge and add tasks to it. Now I have to update this regularly to add new tasks when new problems in OSM appear. The easiest way would be to remove all tasks of this challenge from maproulette, re-create the whole task list excluding those tasks that were skipped by users. But I don't know how to get this information out of the API. Do I have to download all tasks through the API and look at the status field? Is that what the status field is used for. It contains a number, not a string or so, so I am not sure, what it means. (btw: I created unique identifiers, so I could do all that.) Or do I have to only upload any new tasks and leave the existing tasks in place?

How do other people manage this workflow?

Start with the UI and API documentation mentioned in the issue, then determine what the numeric task status values mean and which workflow preserves skipped tasks. Done means documenting whether existing tasks should be replaced or retained and how to retrieve the necessary task information through the API.