No issues using the bars with awning mounted.
Not a Kings, but a Rhino Rack awning on Rhino rack bars.
Awning mounts to an angle bracket that slides in to the track on the underside of the bar.
These are aero bars that stick out past the bar mount.
Haven't got the right photos, but if anything it makes tying the boards on safer as the ties down threads inside the awning bracket and can't come off the end of the bar.
Loaded...

Close up...

Better shot of awning mount...