I see, but something like that would have to take place overnight. Would they be able to get the train from Garden City to VD yard, unload everything, get the train all the way back to Jamaica, then get the train back west to HAROLD to hand the train off to be dragged through NYP and get to their storage location all before the morning rush? My guess is no. I've personally never unloaded a circus train before, but my guess is that it is a lengthy process. When their on the Garden-Mitchell Secondary they can leve the train their and the crews can unload the train as they please. Getting everything in and out pretty quickly could be pretty difficult...especially at night.
Plus their is another obstacle that hasn't been considered...tunnels. The circus train would have to be hauled by MP-15's through two tunnels to get to VD yard. Are the Atlantic Avenue/Flatbush Avenue tunnels properly ventilated enough to handle three MP-15's belching fumes for a decent amount of time (for they're not moving at the quickest pace)? The Dual Modes couldn't be used because they don't fit (which also begs the question would all of the circus cars fit in the first place?)
So while it would be nice to use the yard right across the street, the logistics just aren't there to make something like that happen.