The Racktime Top-it mounts on the blades and over the wheel, hassle free (racks can always be a bit fiddily).
I belive that you could hang a Ortlieb frontroller on that.
https://hollandbikeshop.com/img/prod...38785-11-l.jpg
Btw. I run the Tubus Tara on my Fuji Touring with rim brakes.