It's the little things... This, like Loop Tools and the other "tools" lineup, are essential to maintaining sanity when new to blender. It's one of those things where you think it should just already do that. This is definitely one you'll always want to check the box for. A major mouse mileage and click mileage saver.
Very useful add-on. I really appreciate that I can add new materials to faces without going to properties tab. If I may make a suggestion, it would be very nice to assign material to face from the list of materials used by an object. Currently, the list of the materials show all materials in the scene, and that could be very long. Would be useful to have another list just with materials already assigned to object.
Super helpful. Here is the latest version 3.0.2 - https://github.com/ChrisHinde/MaterialUtilities