I'm not sure I like that idea. In part because of sheer quantity. We have over 170 public exclusives, a fair amount of which only really make sense to release as a group (Prime examples including, but not limited to, the Royal Flush Gang and the Trees of Life & Death/Uprooted Tree). Grouping them into sets of 5 makes them feel more... digestible, for lack of a better word. I feel single releases would quickly become confusing and untenable. Especially for those trying to keep track of releases over time. (ie people who don't check the site/index often and/or who only get notified via the newsletter/promo dept, neither of which include any info on public exclusive designs)
I think we would run into long-term issues if the public exclusives weren't grouped.