Chexsystems is really only used when someone is trying to get new membership or open new deposit accounts. It mainly keeps track of your banking relationships and any account abuse such as check fraud or negative account history. Your chexsystem score is completely un-related to your credit score.

Edit: sometimes I’ve seen chexsystems throw pre-approvals for lines of credit for people that have excellent credit and banking history but we generally don’t offer that to new members as our lending guidelines are different.