I'm not a frequent flyer, but over time have learnt that when going through security or before getting to the scanner, it's much easier to remove your belt and put other items like watch, wallet etc in your hand luggage.
But I'm just a member of the public
Having said that, if you pass through multiple times during the day I suppose it could be a pain. But rules is rules and if I as a member of the public have to do it why shouldn't staff etc.
EF