The EU flights of Iranian airlines are an example of this, but virtually none of the others are; Iranian aircraft with undoubtedly questionable parts provenance

The EU flights of Iranian airlines are an example of this, but virtually none of the others are; Iranian aircraft with undoubtedly questionable parts provenance are flying over myriad countries daily on their way to and from East Asia and South America. Your assertion about countries imposing tight standards on overflights really only applies to EU, US and a handful of other countries; most are not really willing / in a position to do so.