Despite the fact that DCIR has been unsupported for anything smaller than a PT/GP/SCG Open for a quite long time, it seems people have still been using it for some scattered events. Accordingly, a few months ago in this very forum, Andy Heckt announced that DCIR could not be used for any event smaller than 400 players, and anyone attempting to report an event with it would have to re-create the event in WER. Presumably entities like SCG who routinely use DCIR had to specifically get clearance from Wizards to do so, and I'd certainly recommend that you do the same if you feel that it is necessary. For reference, the thread is
http://apps.magicjudges.org/forum/topic/12665/If I'm not mistaken, it is possible in WER to pair three rounds according to draft pods and then pair later rounds according to full swiss pairings. However, I've never actually tried it.