There is so much of her story that does not add up Chris and the choice of Stearman must have been to satisfy primary sponsors Boeing. A DH Moth would have been a near period as possible and there are plenty flying in Africa and Australia despite the 'heat'.
In my opinion The Spirit of Artemis was never planned to "emulate" Mary Heath or Amy Johnson.
It was a high profile
PR excercise makin a semi period reality tv show with plenty of low flying and great vistas.
As for the so called "outreach" I would substitute that for exploitation of the local people enroute to add atmosphere to her film.
By way of example TCT and Ewald arrived in Darwin in no great rush to reach Sydney.
They then flew to Lajamanu which is a remote airstrip a long way west of the normal VFR route from Darwin to Alice via Tennant Creek.
Lajamanu is an aborginal settlement but has a decent airstrip,with Avgas and Jet1. This is the place she described as having Aborigines scrambling for fuel.
Here is the approach from poster sgtbilko
https://m.youtube.com/watch?v=kx53p0u7SWQ
And here is TCT departing with Ewald
https://m.youtube.com/watch?v=wXUf4NoaK3Y
I think they chose this site for the sake of the film they were making to give dramatic effect with landscape and local people.
Her is a short clip on the community.
https://m.youtube.com/watch?v=oKXHXwXRmOk
Darwin to Alice is an easy trip and I speak from experience having flown it.