Actually it is relevant in NZ. I myself reguarly undertake IFR flights from uncontrolled airfields outside Radar coverage and seems perfectly sensible to advise that I am "airborne" to OH or CH Control so they know to activate alerting services etc.
CT7 your argument about estimating etc could be valid but really... is it worth deviating from the sports pages to have a whinge to your Co (or yourself) about it. I doubt it.
I was taught that your Position reports were to be in the PTA ETA format. Hence a requirement to mention the time the position was valid, if it is a the same time as you broadcast it easier to say "this time" than actually report the time. Sometimes you can't get through when you want to so you may want to report that you were overhead Position X at time YY (which may be some minutes ago). Again nothing to distract you from your personal columns.
I'll bet you say as part of your normal R/T when changing control freq etc that "FLTXXX is with you, maintaining..." . That is also quite obvious, isn't it.
Do we know each other, I had a light-hearted rebuke over the NZNR freq, from a Ct7 operator about this very subject.... Is it still nawing away at you???
Cheers
S2K