If you force nl when there is one civilian alive and two mafias then it's your fault if you force NL in false hope of mafia converting you, but it's not game throwing at all because your intention was to win with mafia.
Look it this way: if I lynch one mafia and one civilian is alive, I have more chances of losing with town than winning (if any chance). If I force NL and make mafia hit me to NL again or lynch civilian for mafia autowin then it's alright, however, by NLing you take the risk of backstabbing and not taking the win.
It's a town third party. And it works in the setup as a Killer in Coco's setup (whether to believe Spy or not) and takes the same risk as any town that plays DLYV (Yakuza converting someone into autoloss or them having to hardcarry as solo mafia).
But the setup isn't very good as, even if shooting mafia D1, town is constantly in lylo situations in civilians. It's not impossible, but the effort put in a balance leans towards town since mafia just have to towntell and claim civilian to an 'easy' win.
I have made a lot of setups with the same concept but IDK why it always seems or is unbalanced.
https://epicmafia.com/setup/1363146 this one is the most recent one. Maybe if this doesn't work I could change drunk with mason and add Turncoat again...