Final answer:
A ground person should report any disruptive passengers before the boarding process to prevent any potential issues during the flight.
Step-by-step explanation:
The ground person must report disruptive passengers (PAX) prior to boarding, which is typically during the boarding process. It's important for the safety and comfort of all passengers that any potential disruptions are addressed as soon as possible. Even though airline travel involves several rate-determining steps such as check-in, security screening, and boarding, ensuring that all passengers have a safe and peaceful journey is a top priority which includes managing the behavior of PAX as part of the airline's responsibilities.