Added (medium priority to me):

• Viewport navigation enhancements:

— Resizable viewports in the quad view, so you can make one or two views larger without having to switch to a full-screen view.

— Ability to switch to a left / back / bottom view in the quad view, in stead of having to go full-screen for that.

— A camera / viewport roll control (e.g. middle or right pen/mouse button together with Alt, Ctrl or Shift).