Using screen_loc for HUD elements is common, and while the variable itself is extremely flexible in placing atoms on the client screen, there isn't a equivalent method of retrieving the position of where that atom ends up that doesn't involve some painful manual parsing of the screen_loc string.

As a practical example, say that I create a HUD system that allows for users to click-drag UI icons to different locations on their screen. For the purposes of this example we'll say that we allow them to place it on literally any screen position, and the system sets screen_loc accordingly (e.g. TOP,CENTER+3). Then let's say I want that UI icon to open another UI icon below it when an action occurs ingame. When I want to show that second UI icon, I need to know the position of the first. Maybe I develop some system to keep track of where the user is placing the first icon, but what if the client view changes after they move it? Or the icon is transformed/resized/offset by some other system? It would be easier if there were just exposed variables on the atom to tell me the actual position and size on the screen as a reliable source of truth.

On-map atoms have many methods of retrieving similar data, including the newer pixloc primitive. Why not share the love with non-map atoms too.