Adam, thanks for the pics. My lift uses the same hardware but is laid out differently. I now understand how the cable routing works on yours.
Here is the PVC barrier for when you fill in the front corners. This is simple but it works. This is Schedule 40 (heavy duty) 1.5" PVC.
Here is another good addition to any dock. I mounted the uprights on the outside, so half the bench is out over the edge, and takes up minimal floorspace.