I had intended to include screenshots in the initial post, but I hadn't had a chance to take any in-game and due to the UIBuilder's handling of non-square images a UIBuilder screenshot requires some manipulations I didn't have the time to make. So, having now had the time, here it is, a screenshot of what the default player/groupmembers window should look like.
The blue 5-point star in the player window is the condensed concentration meter—the points light as each concentration bubble is used. (As mentioned in the initial post, the mouseover/right-click isn't working correctly for anything other than the first concentration slot; I'm still looking into that.)
