If you have a Com 2 box then it doesnt hurt tuning it up to the airfield and listening out. As with changing frequencies. When using Northolt Radar and routing via elstree I have on occassion requested Northolt coordinate a crossing for me whilst monitoring, that way I can get traffic information on comm 2, Elstree know im coming overhead, and I can maintain my FIS / RIS off Northolt.
Some will say why waste RT time.....I say....cause Northolt are a great bunch of people with not alot of traffic at times that love to actually do something, and at the end of the day! If they are too busy, they will soon say no! :-)
You can only ask right!