Please add "left + right mouse button" as another alternative to "When should Groupy combine windows?"
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Stardock Forums
Could you add this please? Always active doesn't work quite well for me, since I have several windows open frequently and the grouping happens too often by accident. Holding Shift or Ctrl is a bit inconvenient on the other hand. Holding both mouse buttons would be the fastest and easiest way to group windows imho.