I'm not afraid to use plugs, never ad a problem in my life an I run tires down. As testimony I see a worn down bike tire that was changed (mine)and that little nose cone shaped plug had a perfect mushroom head on the inside of the tire.
On my last tire change, I had that same mushroomed plug, the difference was, mine was covered with balance beads. I changed the tire because I had a very slow leak and couldn't determine where the leak was at, I assumed it was the plugged nail hole. It wasn't. Valve stem.

Regardless, that's my experience. Now, I have an extra taxi tire that will eventually go back on my Valkyrie.