I agree.  Note that Internode, despite being owned by iiNet, do fully

support IPv6 and have done for decades.  I believe they were one of the
first ISPs in Australia to deploy it.

Indeed they were, and it used to be reliable over ADSL. I can't comment on the current situation, however.

The IPv6 experience with Aussie Broadband has been favourable; family members of mine are using it, apparently without issue. It was (and presumably still is) necessary to opt into their IPv6 service via their Web application.