[Romain Failliot]

Well.. I'm not an expert too, but it seems to me that the solution to
your problem won't be solved in Wayland.
IMO, it's the toolkits (GTK+, Qt, ...) that defines the consistency of
the desktop, not the compositor, and each toolkits defines its own UI
guidelines. That's why there often are UI problems when running KDE
and GNOME applications in the same session.

For what I understand, the solution resides on a better compatibility
between the toolkits and a better integration of each one in the
distribution (like what Ubuntu tries to do with its toolkit agnostic
policy).

Regards,
Creak