You can always add a new task to an existing sheet at any time. So, when your other tasks get filled up, you can just add a new task. Note that you can also increase the quantity for existing tasks at any time as well, so there is no need to create a new task just because one got filled. But, if you do want to create a new task, that’s easy to do at any time. It would be the same as “activating” a task… your visitors won’t see the tasks until you create it, and it doesn’t take very long at all to create a new task.