If you using this script (preferably at the start, if you want to have visible only a task 1), so other tasks (tsk2, tsk3, tsk4) will be invisible after a period of time, until you show up:
aP removeSimpleTask tsk2;
aP removeSimpleTask tsk3;
aP removeSimpleTask tsk4;
It should work ...
Was also looking for this too, so thanks! the tasks work fine, show on the map fine, but I cant figure out where to put the above code so that task2, task3 etc are hidden until the previous task is completed