"Maybe when BD gets the second A330 back in service THR will be a route it is used on."
Unlikely. My understanding is that the Iranian authorities will not allow a bigger aircraft to be used on this route. However, if the UK were to reciprocate and only allow Iran Air to use narrowbodies to London, who knows.
Have yet to tech stop coming back from Tehran but I reckon my next one will. The BD932 looks like it's lobbed into Prague this morning....