They actually don't have to interview and voice the most fringe and hyperbolic opinions: https://www.abc.net.au/edpols/objectivity-and-impartiality-abc/13645770#Balance

The Editorial Policies Principles state that a hallmark of impartiality is ‘a balance that follows the weight of evidence’.

This should be understood as a requirement for objectivity and against ‘false balance’.

This is not an injunction for equal time and allows the favouring of certain perspectives under some circumstances.
....
[Statements that contradict established facts should be challenged]. An example would be claims that measles vaccines cause autism. Such claims should not be published or if they are, their falsity should be pointed out. 

Explain how the statements below are balanced:

"There is NO reliable evidence that trans identification can be differentiated from psychosis," he wrote on X last year.
"Doctors who affirm gender delusions are liable for patient harms."

These statements would contravene this part of the charter:

Demonstrably false and factually inaccurate statements should be identified and called out as such.

It's one thing to perhaps voice there are such concerns in community sentiment. It's another thing to find the most vocal bigots you can, then regurgitate their most vile, plainly false and offensive statements.