To my limited experience, if the arrival dive shop reinstalls the valve for you then there is a VIP charge. If you just arrive at the shop reassempled tank in hand with a current VIP...
Yeah, I don't know much about this either, and I suppose customs and practices vary from place to place. Some tank fillers will do all sorts of dangerous stuff, like fill non-O2 clean tanks with 100%, etc...
I guess that workaround might work, but from what I have experienced, if you bring a tank in to a reputable shop for a fill, and the tank is completely empty, a VIP is required.