I'm not sure about the feature you talk about, but maybe have a look at accessibility settings of MacOS. They putted a lot of advanced settings in there targete

I'm not sure about the feature you talk about, but maybe have a look at accessibility settings of MacOS. They putted a lot of advanced settings in there targeted at various kind of handicap. However these feature can also be used to improve productivity. Some developers even uses accessibility interface to add custom overlays & controls (Steam for instance).