swipe up on empty space.

You mean if you swip in one direction on the taskbar (Like Smartphone Tab Swipe), then something should happen? Yes, I think that is good. But you can do it in all directions. If you swip from right to left on the taskbar, for example, then you could switch desktops. If you swiped from bottom to top, then the device should be locked. And so on. This should be adjustable in every direction. Yes I find good. This works best on notebooks that have a touch screen.