What you'll find is if/when it does denonate it'll still look rich on the plug, you'll be safer with 100 octane as it'll resist detonation better but the problem is not the octane of the fuel, it's that lead in fuel slows down the burn and requires advance.
If you're forced to use 92ron at any time I'd personally use the normal card and just deal with it being foul to ride.
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread