I suggest putting red, yellow, or white rubbers on the flippers.
Adjust slingshot switches so they are ultra-sensitive.
Steep pitch might actually increase your game times on these games. Less side-to-side + easier to trap.
If ball-saver is on, experienced players are going to be playing a lot longer. They'll spending more time short plunging and bashing ball lock targets, which will also result in a lot more multiballs played in the tournament.
Wide outlanes but keep the rubbers is the right idea IMO. Though if you keep "Rescue" at factory settings on ST, you might want to consider removing the rubber from that side.
Tight tilt is essential.