They can use all of the above, depending on the level the airport asked for...
(it appears the configurations that NATS uses include everything)
When one compares ADSB data direct with WebTrak, you can spot missing flights on WebTrack...other Countries, with more developed airspace systems and ADSB requirements, can just use that data for WebTrak...(just messing with you)
It is nice to see the full data package that the NATS system provides....