Fires
So, as far as I can gather - some engine fires crash the aircraft in a few minutes, whether by structural failure of the wing (Ansett Viscount), or draining multiple redundant hydraulic systems (Tu-154) or by eating into the fuselage (Manchester B737, on ground). In which case it does not help if the airplane stays within 90 minutes or even 60 minutes of a diversion, or, as shown in Manchester, stays on ground...
And there have been other engine fires which are extinguished quickly and completely... in which case it does not much matter why the engine failed, and the plane can fly on for 60 or 180 minutes or as long as the fuel lasts.
In this light, ETOPS/non-ETOPS distiction seems academic. Are there any flights which were able to make a safe landing directly because of the ETOPS fire resistance/suppression capabilities?