OK I now understand what you were referring to (.ccs). There is no setting with in windows that will allow you to to user PowerBoost for longer then what it was intended to, or make it faster for that matter. That is all contolled by the .cm file that is downloaded to the modem. Now if you are thinking that you want to raise your RWIN, to accommodate for the speed increase, you have to consider the fact that if you make it to large its going to be detrimental to your standard speed.
I hope that answered it some what... if you need me to go farther in dept send me a PM.