Look at it from an insurance companies point of view..
A car with runflats is less likely to crash if it hasa a blowout at high speed, than one where the tyres have been swopped for regulars !!
I had a high speed blowout with runflats & didnt realise until the alarm went off .
I`ve since changed to Toyo`s but had to declare it on the insurance {who in this case didnt alter the premium}