I admit to not having read the whole report, but this sentence rings a couple of bells.
"The absence of recorded tracking data in the last minutes of flight was consistent with previously-recorded approaches, including to Brewarrina Airport that day".
Does it suggest that turning off the tracking data on final was 'routine' ?. If we accept for the sake of the discussion that it does, then it merits some consideration.
If it was routine, then would turning it off be that 'big' a distraction ?.
Do we know if the 'dimmer' function working properly ?, one bright light can be distracting and disorientating, especially when tired on the last approach in the dark.
Do we know if the unit was an 'air switch' (Tacho/VDO) type of recorder used for maintenance time (time in service)?.
Not saying primary cause here, just wondering about contributory factors and eliminating possibilities.
Can anyone who has used this particular GPS unit shed some light?.