Thank you for all the work with Bluefin and Aurora.
I think a different approach to theming QT/KDE apps in Bluefin (and GTK apps in Aurora) would be nice. I recently came across this call to stop theming apps, and I agree with the general gist: https://stopthemingmy.app/.
I think that Gnome apps should look like they would in Gnome, GTK apps should look like they would without any extra theming, QT/KDE apps should look like they would in KDE without any extra theming. I know that “extra theming” is not always a clear line, but I think apps should look like the developers wanted them to look like. In the case of LibAdwaita, trying anything else simply becomes an ugly mess.
However, many distros/DE try to make everything look similar, weather KDE with their own GTK Breeze theme or, in Bluefin, the (now deprecated) QGnomePlatform. The latter adds a title bar to QT apps that clashes with the Breeze colors of the main window and contains hacky-looking Breeze buttons.
In KDE, it is relatively easy to make Gnome applications look like they would in Gnome. In Bluefin, I deinstalled QGnomePlatform to get the default QT Wayland titlebar, which looks decent and uses Breeze colors. I then set QT_QPA_PLATFORMTHEME=kde
for all flatpaks so that all KDE apps look like they would in KDE. I may have also added theme files somewhere. The only thing missing is automatic switching between light and dark theme; I don’t know how to implement this.
Now, my apps all look like their developers intended them to look. I don’t need all apps to look the same, other operating systems do not work this way either, and many proprietary programs, such as Spotify, have their own looks anyway. I think if would be nice if in Bluefin and Aurora, apps would look as their developers intended to by default. This approach also simply seems the least hacky and most clean, although that is of course particularly subjective.
I must add that I am no expert in this area, and I know that it is not always clear what the “default” theme is for some apps, but I think my points do make sense. Finally, I did rebase to Bluefin from Aurora, so this maybe have impacted the theming; maybe any issues I had were because of that, at least in Bluefin.