Audacious, the rock steady no nonsence music player also features a qt interface these days. But I don't think that will be built for the Bionic repositories. Could that be included in the neon repositories.
Audacious is very light and very steady.
Is there kind of an official wishlist for Neon?

Audacious is part of the Ubuntu repositories, so you should be able to install it with the standard repositories:
https://packages.ubuntu.com/search?keywords=audacious

I'm not a Neon developer, but even if it were not part of Ubuntu, Audacious is not developed by KDE, so out of scope for the goals of Neon ("KDE neon will provide users with more up-to-date packages of Qt and cutting-edge KDE software." says https://neon.kde.org/faq )

That is exactly what I want to say:
Built in the right way audacious IS qt-software. So it would go very well with Neon. Like you say:

"KDE neon will provide users with more up-to-date packages of Qt and cutting-edge KDE software."

Only I don't think the qt enabled version will be built by canonical. Or they would do that with an eye on Kubuntu. Now, in the bionic repositories it is only available as GTK app. I think that built in the qt-way it belongs in the Neon repositories. Also because it is incredibly stable and light.

"packages of Qt" means packages of the Qt libraries themselves, not any package built using Qt.