The not needing to stay inside is true of almost all draggable controls on iOS btw. And you can combine that with multitouch. In a music application you might h

The not needing to stay inside is true of almost all draggable controls on iOS btw. And you can combine that with multitouch. In a music application you might have 4 or 5 parameters under your fingers, nowhere near the original controls which are small and close together. Seems to work everywhere.