Is anyone aware of required signage (i.e., on customer service reps desk) indicating that the FI uses Chexsystems? And what about the same scenariou with Equifax?

Years ago we had a Chexsystems sign on every CSR desk. I believe Chex provided the signs but I never knew if it was a requirement or not. Over the years, the signs have disappeared and examiners have never mentioned needing those signs.

It's not a regulatory requirement. The signs are designed to scare off folks who have been tossed out of other banks (that presumably reported them to ChexSystems).