It works the same for packages in USPS informed delivery.

Here’s an example from last month.

That’s good design on their part :)

Most games have the ability to capture the mouse to prevent the moving across screens issue you’re having

For the mirroring flipped monitor I would think the easiest way is to get a desk mount with Vesa and rotating to rotate your main monitor 180 degrees while you’re drawing

I don’t know of a software solution for this unfortunately.