I currently use Plasma for my Github work, but I like to have a backup just in case.
So, I have been experimenting with Sway and Dolphin, konsole, & kate. A dark theme is also a must have.
Using qt6ct I have successfully got konsole and kate working with Sway with a dark theme. Dolphin is the sticky wicket, this is the closest I have come so far.
I typically use Kvantum for theming Qt apps on Sway, it seems to be reasonably consistent and has some decent themes. Make sure to set QT_STYLE_OVERRIDE=kvantum somewhere in the user environment, then all you need to do is set a theme in Kvantum Manager.
I personally don’t use KDE apps outside KDE because theming is pain, but I think that qt6ct-kde is tool what you need. It is just patched qt6ct to fix theming issues KDE apps.