Maxing the PF multiplier (upper ramp loops) is very important. After 10 loops, complete W-H-O for Sonic Booms (10M x multiplier each shot).
After locking 2 balls and the Time Expander rises, select Dr. 7 to help you start Multiball faster. He doubles your white target hits.
Every time you launch a ball (even after a lock) you can select your doctor to help you. Choose wisely.