It is my understanding that a person's name stays on Chexsystems for 5 years. I don't know if it is longer when there are amounts owed. If your bank is making exceptions and documenting objective reasons, you should be OK. For example, if a customer was reported for owing OD fees and now shows as paid back, that is verifiable if questioned. You want to look at the reasons for the person being reported and be sure to avoid any factors that could lead to disparate impact, such as opening balance, geography, etc.
Hope this helps.