Beware the rationale that you are audit compliant simply because your goods have been Green Routed to move through a border. Products are often given the go ahead based on information declared and which on the face of it looks legitimate however, errors and misdeclarations lie therein rendering these declarations noncompliant.
The word customs agent can mean anything from a person who inputs data on a template to a highly competent specialist. Also, the area is fraught with complicities and such a broad spectrum of coding, legislation, regulations and conditions so a specialist in one area may not have the where with all in another.
You as the trader are the culpable party so in order to protect yourself and your livelihood, you must choose a capable customs agent for your perfect fit. Ensure that your customs agent has the level of competency and expertise that is required to keep you informed, educated, audit compliant and safe from the trepidation of noncompliance further down the line.