Why are multiple selection schedules only available on the unlimited plan?

There's a good reason for this - if you're are able to select entire collections etc then we just don't know how many products are actually going to be scheduled at the time of publishing/unpublishing. As far as we know, you could add 1000 more products to the collection in the time in between! 

For Auto Schedule, we don't charge based on arbitrary features that don't really have any actual relation to cost. The main thing that costs us is the actual processing of schedules so we base our plan charges on this.