I know it's recommended that those with the MC mounted on the frame rail should use a residual pressure valve to help eliminate pedal travel, but I have the same issue & mine is mounted on the firewall. Shouldn't that work in my case as well? Looking at getting the 2lb valve since I have disc's on the back.
They just help kep some of the pressure at the wheel so you don't have to pump more fluid to work the brakes. If you still have flowback, yes try them.
