I purchased, cut to length, and replaced the grey tank cable on my own. I was able to just shorten and reroute the black tank cable. Both cables now have almost a straight shot with very little bend in them and they work just fine. I did not have to replace the valves. Now, they are easy to operate, and do not leak. All is well.
I contacted Brian Clemens about them when I was having the problem, but didn't push it. I did not ask for reimbursement since I was able to do the work myself and the cable was not expensive. I used a Valterra cable for the grey valve.
FR could easily cut those cables to the proper length before installing them at the factory. It would take a few minutes per cable but would be easy to do on the bench -- much easier than after the valves are installed.