Need help with the co-planar command.


Select co-planar is one of my favorite commands in blender, but I am starting to think that maybe I have the wrong idea about what this is suppose to do because it acts (from my perspective) a little weird. Here is an example,

If I select a face that is pointing upwards in the scene and run “co-planar” not all faces will not be selected since the value is to low,so far so good. But when I crank up the value to select the rest Blender often highlights faces that are facing a different angle and have higher angle compared to some others.

Am I misunderstanding what this script is suppose to do?

If you know a script/different command that does what I am after please let me know! I have attach an image to show what I mean. The red faces should not be an option.