A long, long time ago I was involved with UPS bringing the 757 into KBUR. The "supervisors" were UPS employees and the ground crew were contract, the MX was UPS something or other, the company was apparently split in two. They had the trucks and the planes but trying to mix the two was a mess. Supervisors were shiny young college graduates with absolutely no experience and a bunch of "Rah Rah" nonsense they heard in some hotel conference room during a training event. I'm sure the nickname "Cargo Nazi" still floats around in unwoke break rooms. It would not suprise me at all to have some UPS drone insist that someone wear an official visibility vest over a visibility vest they might have already been wearing. I actually look back fondly at that time in my life, it confirmed everything I suspected about scientology.
There was a pilot at Martex that had a "safety yellow" jacket complete with reflective stripes. The UPS ramp manager made him wear a safety vest over the top.