Combine First Last and everything in between

If you want your subscriber to finish after the first one then use .first()

If you want your subscriber to wait until the last one then finish then use .last()

If you want something in between you use .output(in:) which accepts a range to specify which posts to respond to before finishing. It’s not the most intuitive sounding name, but it does the job. Also .prefix() seems to be derived from it.