I just bought the pro version of Mixing Station Xair - well worth the money for the Pro version. For $5 I was able to solve a wish list item - I now have a layout that includes the 4 mute groups One option of the Pro version is a fully customizeable layout.
Well done and well worth checking out. THe lack of an Android app was one reason I was holding off on X32, but I see now reason to not use Mixing station for that too
Thanks Mixing Station