You restrict the freedom of your cursor with this kind of gimmick, though. You can't use the mouse over macro AND look/rotate around as you'll need the cursor on a target before the spell is being cast till it's actually being cast. I don't think the whole "one extra click" reason make it worthwhile to use a clunky macro. You can change your target while on cast/GCD and queue up your next spell/ability without restricting your mouse on top/next to the party list.