Freeform is great but missing a key option...

So you can freely draw in Freeform and then erase any parts you don't want, cool. Or you can make shapes and lines and arrows, also cool. What would be super cool is if you could make a shape and then use the eraser tool on a part of the shape. Maybe include an option in the shapes context menu that would let you "convert to drawing". Any chance of this being added at some point?