Well, as long as we're free associating, they could just put out say 3 or 4 boxes of knives, a wide assortment of types, every day for two weeks or until they sell as many as they need to, and let people send in their names and preferred dates to come. People who had flexible schedules could let Spyderco schedule them, and an attempt could be made to accomodate people who had a narrow window to come.
The scheduling would be a bit of a nightmare, so they could just put out 4 boxes a day and hope people would come in randomly. I'm sure people who lived nearby would sneak in every day, etc, but whatever
Or, it would definitely squelch the carnival atmosphere of the sale, but they could, until the pandemic is over, just leave a couple of boxes on the counter all the time until they get the stock reduction they need. If people who live nearby showed up more that 2 or 3 times, they could consider putting limits on them, or put up a sign saying they could do it only once, once a week, or whatever.