At what point is the flight no longer scheduled for more than 6 hours? There is an open ASAP report on this issue. I believe the feds are researching the intent of FAR 121.621 and whether it is abuse of the regulation to plan on deleting an alternate before the release is even signed. If the feds say we can do then great. In the mean time be careful what policies you follow out of the Anchorage Operations Manual.