I had a plugged tire on my pickup explode. Probably because of loss of pressure while I was driving. It happened about 20 miles after I left the shop. For autos; no good tire shop will plug a tire. Automobile tire manufacturers definitely recommend against it.
After plugging a tire, the GS manual recommends a reduced maximum speed (pretty slow) and tire replacement.
Just remember that all of the control forces are transmitted through the tire/road interface.
I agree that if you are careful, the failure is a low probability event and many people have used plugs successfully. The possibility of tire failure is, however, significantly increased. If I can eliminate a risk for a few hundred bucks, I'll do it.
The difficult part of safety is that you don't get any extra, you just get to keep what you have.