N3V Games (the devloper of the Trainz franchise) is based in Gold Coast, Australia. They might be willing to devlop some addons or assist with research. I don't realy see Trainz as a competior to TSW as the two have become quite different from each other. I might also benfit N3V as trainz is kinda dead, their last 2 games according to steam db had a player peak at 623 (Trainz 2019) & 358 (Trainz 2022), while TSW had 2154 (TSW 4) & 2638 (TSW5)
Steam is not the primary platform for Trainz, many users buy direct from N3V or use their subscription model. Personally I would say the chances of N3V helping DTG with Aussie routes is about the same as Run 8 offering help for US stuff. It should also be noted N3V do very little route or rolling stock development themselves. 99.9% of the content is produced by third parties whether the tiny bit of payware or the more common freeware. Even then, there's not that many people doing Aussie content - the guy who has done the big NSW modular network and maybe a handful of others. Also much of the Aussie rolling stock in Trainz is ancient, dates back to TRS2004/2006 era and even the newer stuff aliases the existing cabs and sounds, often totally inaccurate. So while it was certainly worth airing the idea, I don't see it happening. Also fair to say those developing for Trainz are pretty fanatical about... Trainz and are not going to be inclined to jump across to a rival product, which also requires much higher skills to work with.
I do agree that the chance is near 0, but at the end of the day money talks and then at least dtg can then say they tried. I still don't have high hopes that this would work but you don't know unless you try.
The trainz people are bringing their game to the Xbox series consoles so will be tapping into a whole new market for them, and from what I read a bit ago meant to be landing before end of the year but couldn't find any exact dates......
