Desertflyer there are plenty of old bad ideas. Refiling enroute is one of them. If fuel to destination plus holding plus diversion is the safest way, then it is the safest way regardless of the customers underwear. I'm sure he would rather leave his packed underwear behind for a day than leave the ones he's wearing hanging from a smoldering tree half a mile short of the runway.
If its safe to do refiling sometimes then its safe to do all the time, If its not its not.