Never seen this suggested before but basically we've all seen situations with saves that are 9-3-3, have 5 town randoms, and 4 of the towns end up being citizens. This is obviously not intentional and kinda dumb.
What I want is an option for any random, town random and mafia random in the setup to never give the same role twice. I've seen this problem many times but I was reminded yesterday when a triple town random was all citizens and a double mafia random were both mafiosos.
And remember, if you're insane and like the idea of your any randoms giving 3 survivors and 2 serial killers then you can leave the box unticked.
Also, consider having it auto-on? And why stop at these 3 randoms? Why not all randoms? (but for the other randoms it's auto-off because it's nowhere near as bad as it is for other randoms)