Re: Nailed in the shoulder:
IMO...it's a 50/50 thing. I've seen tires with plugs blow out even when the plug was in the middle of the tread. (where they are meant to go).
Depending on how you drive, it could last, or maybe it won't.
I won't EVER own a tire with a plug in it! With my luck...that's just asking for impending doom!