After watching Freezard's run, i though that the obvious optimization would be to mine with your starting SCV while the Command Center is still sliding, but after hours of tries, it seemed impossible. The thing is, if you tried to get back the minerals to the CC from the front, the CC would stop sliding; If you tried from behind, the SCV would just follow the CC until it stop. By sheer luck, just before giving up, i found an easy setup that allow the SCV to get the minerals back :D