Ability to temporarily flip canvas horizontally (mirror view) for design checking
For illustrative purposes, it would be really handy to be able to temporarily flip the canvas horizontally as if in a mirrored reflection.
You would instantly see slight imperfections in a design in this new angle that was not previously noticeable due to one's specific viewpoint.
A lot of graphic programs do this to allow scrutiny from an alternate angle. InDesign and Photoshop do this already of course.
Jessie Kohn commented