Kit price change: Downsizing

What have you done to downsize your email list? What do you recommend and what do you regret about cutting down your list to size?

I need to cut off some people so I can move to a lower tier in Kit—why pay for people who are not active? So I need to decide if I should cut off “anyone” who hasn’t opened my emails—or use a different standard.

I do recall a previous question asked of Thomas where he said some recent upgrade results with false positive opens and false negative open reports.

Would love to hear your ideas and experience.