Genghis:
You really do not have any idea of what you preach when it comes to wearing hi-viz jackets on the ramp at Liege.
You were obviously there during the day when very little is happening.
If you had been on the ramp at midnight with around 50 aircraft and 200+ vehicles charging around, you would bloody soon change your mind.
I flew for TNT for 19 years so I know what I am talking about. The flying was great but the ramp at LGG had the potential to be potentially fatal.
In fact, I remember some friends of mine, who got off their Merchantman one night at Brussels on the DHL ramp and who refused to wear hi-viz jackets and were wearing their long dark airline raincoats in the rain when a vehicle mowed into them. I don't think the captain ever flew again and the other two were injured.
Perhaps Liege should bring out a NOTAM just for you stating that hi-viz jackets are not required whilst you are visiting the airfield in daylight?
I am sure that your commercial clout will overcome any other considerations.