I've just reverted this changeset - see https://www.openstreetmap.org/changeset/161665924.

1. The maxspeed through Nimmitabel had been previously changed at changeset https://www.openstreetmap.org/changeset/108249041 with comment "Updated road to new posted speed of 50km/h (from 60 km/h)" (implying an official maxspeed change in or prior to July 2021)
2. When I travelled through Nimmitabel in November 2024, the road was signposted maxspeed 50.
3. Many of your other edits have been "based on NSW Speed Data". You didn't state the source of your edit for this changeset (despite me asking you twice), but if you did, the maxspeed on the NSW Speed Data map is currently 50 (not 60).
4. Your edit left a 200m section of the highway at maxspeed=50 (implausible)

For your information, I have noticed some errors in the maxspeeds on the NSW Speed Data Map, so it's probably best not to rely on this as a data source. Another user in the last few years was using this data source, with mixed results (some were correct, but some were not).