As far as I know aging in Winoms is hard coded off the date of service. You can change when the patients receive their statements to last visit via Cycle billing but not aging. Possibly other offices can provide feedback on the Community how they manage aging with the patients since its based off date of service.
We have also not found a way to edit it or take it off of the patient statement. We either write a note to the patient or cross it out with a sticker or permanent marker. It is not elegant, professional, or timely, but it saves angry phone calls from patients about only receiving one bill and being 90 days overdue (for instance).