I have heard from somewhere that in Epic Mafia/Forum Mafia, there is a rule that disallow abstaining in trials, where if you abstain you get some sort of mod-kill (Lightning strike). I would really love to use this setup in inhouses. My reasons:
1. This makes evil roles votes smartly, rather than just abstaining and giving themselves away.
2. This forces neutrals to vote. Basically preventing them from blocking lynches and forcing them to choose their sides.
3. Forces indecisive towns to vote, many towns tend not to vote in case of an Executioner/Jester suspect, and more importantly not voting on a potential town which ends up being guiltied by mafia and neutrals.
Remember that this is only an option, and only allowed if the host decide to do so.