A minimize function like that should actually get the content out of the way. Imagine the color window at the bottom right of the Screen: You minimize the panel and what‘s left is a wide rectangle in the middle of the Screen… Not good. There are multiple ways to solve that (like turning it into a smaller shape like a circle, moving it into a corner, swiping it out of the screen temporarily, etc…), but just leaving the rectangle in place and not even the reducing the size is an incomplete implementation, especially when working in fullscreen. The double tap is only necessary to activate the function, there is enough space for that anyway. When minimized, it can be made a single tap, or swipe or whatever.