BolZup,
I have not found a cockpit with a FPS display containing the wake turb cat of all the aircraft that may affect my flight.
Thus the only way that I can becaome aware of a heavy in my vicinity is to hear it on the initial call.
Isn't the heavy followed by light the one category that requires more than 5nm radar separation in trail?
Packing in aircraft on final approach is only a very small part of the operation.............what about VFR zone transits, class G operation etc etc.
Overall the requirements are that it is used and for all the R/T time and effort it takes I considder it a good safety measure.
Remember also that the UK treatment of VFR flights and the ICAO system are different.............UK takes a more proactive approach with VFR flights.
Perhaps you would prefer that the requirements was to make the "Heavy" call in class E, F and G airspace and then there are VFR flights known to be in B,C,D airspace and etc etc............no actually lets keep the current requirement which is both simple and safe.
Regards,
DFC