It is somewhat simplistic to state that the radar data is not used by Maestro. Maestro is sold by Sofraevia with a version that does update from radar, however in Australia this would be of limited use as there is only limited radar coverage.
Maestro receives updates from the electronic flight plan that is held in the Eurocat system. The electronic FP in turn receives regular updates from RADAR, ADSB, ADS and Controller input.
If you are on a long sector it would probably be worth updating Cruisin TAS / MACH which the controller can then input to the TAAATS electronic flight plan. Even better review the company FP so that it is correct when submitted.