Dash should remain full-size if user closes and re-opens it. Dash needs to offer way to "un" full-size it.
At higher resolutions the dash is not full-sized, but there is a button at the bottom corner which full-sizes it. This does basically nothing, because the next time you open the dash it returns to its original size. There should be a way for users to set its default behavior. I propose making the maximize button save the dashes state.
Also, there's missing a way to return it to its smaller state after it has been maximized. If you allow the button to save its size state then you would need a way for it to return to its original size.