Hi John, what you are describing was to be one of my winter tasks. My problem is exactly as you described, the regular shackle can get caught in my bow roller. I did have an oversize SS shackle though.
The problems I have are 1, there is no place around here to buy a swivel so it has to be done on line. 2, no place, catalog or website, had the inside dimension of the swivel so I had no idea which one to buy to fit over the thick shank of our claw anchor. 3, our claw anchor has a slot, not a hole, so what I understood is that the swivel can ride up over the top of the anchor and like Larry said, the anchor becomes a big lever arm plus does not set well when that happens.
My answer to this was to go to a smaller shackle instead of the swivel. Even though I always use the rule of thumb of going at least one size larger on the shackle then the chain I felt the smaller shackle would be no more of a compromise than the chance of cracking a swivel.