It's often useful to skillfully drain balls to send them back up to the upper playfield when the ball saver is active
A good stack is Ace in the Hole, No Limit Multiball, and a Poker Corner mode (Change Gears, preferably). Start the Poker Corner mode first.
Poker Corner modes are qualified by completing poker hands (left and right ramps). Starting Poker Corner re-qualifies Ace in the Hole.