What about to have profiles, so if you wants the application to only run in screen saver you have one profile for that. And if you are doing something that doesn’t need much CPU (like writhing or surfing) you have one profile that make the application run all the time.

Or it could be making easier to turn on/off “Run only as Screen Saver”. For example if you right click on the icon beside the clock you could change it from there.