I would rather change in Sydney than start and end my journey in Sydney.Cheers, I think someone on this site alluded it’s simpler than the old days? I did change once in Sydney for Vanuatu. Ages ago. I usually avoid changing in Sydney, strangely?
I have been doing this a few times a year since 2012. When I check in at Canberra they check my flight and change it if it is running late.
Forgot to say, this only applies if on the same or an associated airline.
And if you are transferring to a domestic flight in Japan there are a lot of options other than Tokyo.