The problem with getting rid of the boom has to do with sail shape. When sailing on the wind, this can be corrected by using the proper sheeting angle but off the wind, you won't be able to get the correct sheeting angle. As you fall off farther, you want to sheet the sail more outboard to keep it from bagging too much and this simply isn't possible. Think of it just like a big genoa. I suppose if you found a compelling reason to try this that you could work out a whisker pole for downwind sailing but at that point you might as well just use a boom.
I have sailed many loose footed traditional vessels and almost all have 2 sheets which is almost as dangerous as having a boom. Some boats with a single sheet lead the sheet to centerline which gives terrible sail trim. A traveler is pretty hard to get to work correctly without a boom although a rigid track one can work. Unless you get a traveler to work, you won't have a self tacking sail anymore.