Note that IntegraXor has an auto-fit feature which will always ensure the whole mimic could be seen in any size of window, monitor or resolution. As such engineer doesn't have to worry about the finally used monitor size or screen resolution, and don't have to bother one same screen to be view over different sizes of monitor across different devices.
Document properties.
Engineer is then advised to turn on the visibility of drawing border like the screen shot and always draw within the border only. However, if a rectangular background is needed then it should be drawn beyond the border with excessive size, so that no edge of white spaces will be shown when screen is resized. And since space outside of border might be shown when window or screen size is not matched with the mimic, engineer shall avoid to place any temporarily item or clone's origin outside of the border. Instead should consider creating one extra layer to keep temporary item to which shall set to hidden.
Display will always fit to border, so background rectangle is best to drawn three or even five times the height and width.