Discount won't touch it, most won't repair that. I would've back in the day, hell I would've plugged it!!!. If you have a cert. it's definitely a road hazard. Good luck
The only plug you would get to hold in that would be a cen-tek. Yes it is in a non repair area, as any repair done by a reputable shop must be farther than 1" from the side wall. It can be plugged, but they cannot legally do it. Cen-tek is a plug patch combo, just in case you have never heard of them.
Just to add, this is why you buy NEW tires from a reputable retailer. If I had used tires, I would just be S&^t out of luck. Gonna start saving for my next set of tires now even though these still have a long life to go. I want bigger tires.