Navigation Cube disappears during sketch edits! Why?

Why does the navigation cube disappear when I'm in 2D sketch mode?

I still want the ability to swing the part around to see and measure things. I can move around the part with my mouse buttons or spacemouse, but not the cube ... because it disappears. It's not as if my view is locked to being perpendicular to the sketch plane, so why can't I still use the navigation cube .... Arrrrrrrggghhh!

To repeat a previous post. If you are allowed to do an UI operation, give the user the controls to do it. If your not supposed to do an operation, then take all of them away. The key to usability is CONSISTENCY.