Hi Flash
The screw 'in' OCS isn't a standard OCS for the Denk II Binos but something Denk designed subsequently as an additionally accessory - it essentially replicates the OCS system they originally had in the Denk 1s. The vignetting is dependent on the F ratio of your particular telescope relative to the eyepieces used. It is only an issue when using low power eps above roughly 22mm. As all of this was a bit confusing and frustrating for some when they experienced vignetting with the standard OCS systems from the Denk ---II s they redesigned their Binos slighly with a greater/wider degree of light path travel and 27mm prisms which solves the problem completely irrespective of whatever Denk OCS you might use. The catch of course being that the new Denk Binos are roughly $1500 but will provide a slightly brighter image for that price.
Take home message to all of this is that none of this is really a concern unless you are trying to use EPS above 22MM and then only in certain telescopes