1.) If the Mafia send me their kill, this indicates that the Mafia have night-talked and hence are comfortable with their kill. For other roles which are singular (such as Doctors, Cops, etc.), I try to keep night going for at least 48 hours so that if they have a sudden burst of insight, they can always switch their night-target so long as I haven't opened up the game.
2.) However, if I open the game immediately after a mafiate has sent a kill choice, this gives away too much information in the sense that:
-> A.) The town will know the mafia is active (or at least was on or around the site during the night)
-> B.) The mafia knows that if there are any town power roles, they must have been active during the night
As such, I try to make all of my nights in all of my games have a minimum of 48 hours... and I also make sure that nobody happens to be on vacation with no access during that time so that they cannot be 'cleared' through circumstance. Even if that does happen, I will often PM these players ahead of time and ask if they would like to send in an
early
night-choice.
Overall:
The mafia has a duty to hold off sending a kill if they wish for night to be longer for discussion reasons,
but
the mod
always
has a duty to not give circumstantial information to the players if s/he can help it.