My fiend's BMW X3 AWD rear right, run-flat tire got a quite long cut by that triangle shaped steel object in the picture. We got it plugged and it has not been leaking any air since the last 24 hours:
However, as far as I know such long cuts really should not be fixed with tire plugs. What is the reason behind this? Could such repairs manifest in anything else than a slow leak returning? For example, something like a tire blowout that would make the driver lose control of vehicle at high speeds?
Also, these are Pirelli run-flat tires with side wall reinforcement that should be drivable with 0psi pressure for 50mi at 50mph speed. So I would imagine that, if the worst case scenario is that the slow leak simply returns, then my friend will replace these almost worn out tires with new ones, if he really has to.