By the way, using a quill-AHead adapter to extend the steerer is a terrible idea, because the headset preload will become contingent on the accurate positioning of a quill under all of the service loads. The whole reason why we dumped quill stems in the first place is that they waggle about under load, because the interference fit inside the steerer is several inches away from the load, separated by a length of rod which is necessarily a clearance fit inside the steerer.
By the way, using a quill-AHead adapter to extend the steerer is a terrible idea, because the headset preload will become contingent on the accurate positioning of a quill under all of the service loads. The whole reason why we dumped quill stems in the first place is that they waggle about under load, because the interference fit inside the steerer is several inches away from the load, separated by a length of rod which is necessarily a clearance fit inside the steerer.