Is there a way to trigger the next wave early in DG2?

I know you can speed up the enemies by pressing  but this is slow. When playing the 100 wave grind it just gets really boring when you know you have enough to last the next 10 waves. Is there a way to trigger the next wave of enemies to come early instead of having to wait after you have cleared the previous wave quickly? 

Pressing R1 is the only way to speed things up unfortunately. There have been many levels where my defenses at the gate wipe enemies out immediately, which makes this all the more annoying. I have tried pressing buttons, but I don't see a way to speed it beyond the R1 speed up.