I would not. You could run a new wire from the socket direct to the battery (with an inline fuse) to get full capacity and no risk of frying anything expensive. My guess is that since the light on the dash shows the socket as being used, I would not want to run 10-15 amps thru, parallel or near the dash. If you had a problem, it could kill your dash and since the only time you'll be using the socket is when you are pumping air (while standing on the side of the road) you know have a live socket in the met-in box is not a risk.
