I discovered an interesting bug the other day that allows you to stack modes in Judge Dredd. If you collect the first sniper tower hurry up and start multiball while the second hurry up is still running, it the mode will not stop like usual. Instead, the mode will continue to run during multiball. Moreover, the next mode start light will relight during multiball, allowing you to start another mode during multiball. Even more unusual is that you can stack in a second mode as well. You can only get as many as two modes going at the same time. After all modes have finished running, things seem to get back to normal.
Unfortunately, things don't behave exactly like you'd expect during mode stacks. For example, I tried stacking blackout with regular multiball in the hopes of hitting double jackpots, but for some reason the jackpots will not light during this stack. Stacking bad impersonator with multiball is a mess, because both modes want the center drop target in different states, so the center drop target goes up and down repeatedly. I was able to stack blackout with ultimate challenge (very hard to pull off), but the ultimate challenge jackpots aren't doubled.
Has anyone else found this bug? Is there a way to exploit it for big points? Right now, it seems like something to be avoided more than anything, but it would be neat if there is some scoring potential in there.