Since we now have the 'windows popup' (see screenshot), I think the best way to merge windows is if you can drag & drop a window onto another window in the windows popup (now you can only change the order with drag & drop).
Since we now have the 'windows popup' (see screenshot), I think the best way to merge windows is if you can drag & drop a window onto another window in the windows popup (now you can only change the order with drag & drop).