In the Scottish ACC, there are very few airfields where we can see traffic 1NM from the end of the runway since we use remote radar sites and only tend to use the airfield SSR (Glasgow and Belfast only) as a back up source if the en route radar fails.
For the Scottish TMA, we never know if the approach radar has worked the aircraft and identified it, or if it has come straight from the tower. Hence we identify it.
For Aberdeen and Belfast TMA departures, I don't see any reason why we can't accept that the SSR approach unit having already worked the traffic has done the necessary.
I suspect the fact we need to identify aircraft at Scottish might be a cover your ass procedure since the code callsign conversion databases are not linked between our unit and the airfields which could lead to Swiss cheese error with the airfield thinking all is well but with the wrong code or callsign showing on our display.