Could you make it a square? Because looking at it you can only make it like 1mm bigger before you come too close to the usb cutout below. (I also tried an optical cable that didnt fit the hole on the 502 housing. Not by much so maybe 1mm is enough). If it`s square you might get some extra wiggleroom. Just thinking along here. I don`t use the optical anyway. edit: And yeah I know that a square doesn`t take a larger plug than the circle...but you could extent it upward/sideways a little further.