Nearly every dialog in Fusion 360 has a Cancel button, but not the Edit Sketch dialog.
There are many times when I bring up an existing sketch and decide to make some edits, bringing up the Edit Sketch dialog. I start working on making some changes, additions, or deletions and then realize that I'm not really accomplishing what I started out to do, maybe I'm even messing things up on the Sketch. So what I really want to do in that situation is CANCEL the edits. But there's no way to do that. Instead I have to carefully backup, undo the changes I had made and then get out of the dialog.
So, please, add a Cancel button to the Edit Sketch dialog. Maybe have it pop up a verification dialog so that you don't inadvertently cancel something that was perfectly fine.