I'm trying to make an app that requires a canvas sprite to move on top of the map component, and I have enabled the ExtendMovesOutsideCanvas checkbox under the Canvas properties. However, enabling the checkbox has done nothing. Does anyone have any fixes/workarounds?

Welcome Jack.

That's not possible Jack. You cannot place an ImageSprite on top of a map component.
You can place an image of a map in the background of the Canvas.

Perhaps I don't understand what you are attempting; a more through description of what you want to do would help us understand the problem. You might show the Blocks you tried.

Edit the coordinates itself. You can't drag stuff off canvas.

Unfortunately the documentation here is a bit lackluster. The property is mainly about dealing with the touch events and how to constrain whether those events are reported via the event handlers. If the option is unchecked, then events will not be reported if a touch starts in the canvas and then proceeds outside of the bounds of the canvas. If the option is checked, those events will occur, even if the x/y coordinates are outside of the bounds. Sprites cannot be positioned outside the bounds of the canvas, so knowing that the touches go outside the bounds are only of limited use.