The whole point of the 100 and 900 hour limits is to put a cap on work-load.
Adding non credit duties onto Crew who have reached their legal limits is totally absurd. They should be recovering to resume duties once they are below the legal limits.
Duty cycles are now currently so tight, it will be difficult for anyone to do aircraft positioning prior to their report. So you can expect this to occur at the end of a trip.
Example, you operate JFK to HKG 18 hour FDP. Then push-back so you can taxi off the gate to a remote bay. Then you go over to HAECO and taxi another aircraft to a bay. Then the same again so you can taxi another aircraft to a bay. Then you go and start your recovery period.... but wait a minute. You are on a continuous duty, so tomorrow you are doing a NRT turn-around.