I'm well aware of this issue. I don't expect windows to look the same to each other. I like that the title bar can have other content in it other than just the app name and the close button.

For that reason alone I avoid Qt apps, as almost none draw their own title bar. Qt apps aren't even consistent among themselves in theming/style, for example the only apps that look in place on KDE are specifically made with KDE in mind.

I don't understand where the "consistency" obsession comes from, all these apps use different tool kits and will look different regardless.