In my experience, bedding issues are evidenced by "wandering zero". I struggled with this until I realized that the knox form must be independent of the forend. Now when I bed a Lee, I try to get good contact with the metal from the forend screw and forward, and back on the flats of the bottom of the receiver. I also bed the knox form, and then scrape it until I have a sight line. It does not have to be a big gap; a very small one of just a few thousands will do. This prevents the forend from pressing against the knox form and applying variable pressure onto the barrel.

Although I haven't tried it, I think that tying the forend to the barrel with a barrel band or even a cross pin would be beneficial. As I see it, the forend of a Lee rifle should be just a place to rest the hand. I would be happy to entertain other ideas if anyone has them.