I have been studying up on dust collection systems, learned lots. According to Bill Pentz's site, one should enlarge all existing 4" ports in our machines to at least 5", if we are to capture the really fine dust which is most damaging. Apparently even a short neckdown to 4" will kill the airflow to the point that the fine dust will not be captured. Has anyone here actually modified their machines to expand the dust port to 5"?