Ah dangs, I thought that for a moment and didn’t include it in my questions. I knew it was for that photoshop behavior where you rotate the canvas to draw.
Maybe you can make a keyframe for both the camera and the canvas. Rotate them however you want and just flip between the keyframes in the timeline to make them the orientation you want in an instant. Better yet, make a master empty and parent the camera and canvas to the empty and just rotate the empty to the orientation you want and keyframe it.