It’s a shade under. I know in my experiments the top left corner should be set to 0.01 inch in from both the top and bottom
I think the easiest way to mark the corners is to use squares, or disconnected corners. Place one in each corner and nudge each one so it is as close to the corner as possible before turning gray.
Remember that the speeds of your operations-xespecially if there are engraves—will change the allowed edge positions.