First I am not an expert on how things are done at GC.com. I do believe that submitting the PQ actually schedules it to be sent whenever the GC.com PQ server gets to your qurey.
I have read that a PQ that you just submit takes priority over one that you schedule and receive on a regular basis. ......poppy
May those who love us, love us. And those that don't love us, may God turn their hearts; and if he doesn't turn their hearts may he turn their ankle so we may know them by their limp.... An Old Gaelic Blessing