You may misunderstand the statement. First, I always have a tether on the anchor in the event the windless decides to deploy on itself or the clutch loosens. I have an stainless eye bolted to the deck on the pulpit with a small carabiner, which I clip into a chain link. Once hooked you can release tension on the chain with a small bump down. The anchor stays in place and the chain is still tight enough that the anchor is still secure. You can be less sophisticated and just use a small line through a chain link and tie it back to the cleat. With that said, I think the manufacturer is more concerned when using the anchor. It is a best practice to tie the anchor rode off at the cleat once deployed and release tension on the windless. This way the cleat is doing the work and not the windless when anchored for a long period. This will reduce stress and also in the event that the clutch slips you won't be letting out all your rode. If I were fishing and using the anchor temporarily I would not worry about securing the rode to the cleat or securing the anchor with a tether since you would have to keep going up to the pow each time you were moving. Just be prepared to stop immediately if the windless decides to deploy anchor on its own. If I were doing a long run at speed I would secure the anchor.