I'm not sure if anyone has come up with an idea like this or has already developed a mod like this. If so, I apologise.
I think a cool idea for a mod would be 100% trust based.
The game rules would be as follows:
-Anonymous votes MUST be on
-Confirm ejects MUST be off
-Visual tasks MUST be off
-Crewmates finish their tasks as normal, however all tasks getting done does not equal a victory. Instead, as each Crewmate finishes all of their tasks, they each obtain one emergency meeting (each Crewmates needs to finish all of their tasks in order to get a button in case that was confusing)
-Crewmates can vote off all impostors, but this also does not lead to a victory if no impostors remain.
-Voting process is as usual with an additional "All Crewmate" button
The name of the game here is not to finish all of their tasks or to vote off the impostors to win. In order to win, every person in the game has to come to a unanimous vote that they believe everyone still presently in the group is, in fact, crewmates.
There is no limit on the amount of people that can be present in order for people to press the button (i.e. you could press the button even with 10 people still in if you wanted to). The only way to figure out whether you've won or lost is to either trust in everyone you're with and vote "All Crewmate" or continue the game and let the impostors potentially kill all crew one by one (assuming they're still in the game).
Meetings can only be held if a body is found, or if a Crewmate 'unlocks' a meeting button by completing all of their tasks.
Impostors can still sabotage, even after death, so the potential of dying by emergency is still there.
The main reason why I think this could prove for some very interesting gameplay is because it's 100% based on trust. Crew can't just get an easy out by completing their tasks. They can't physically verify each other with visual tasks. They have to fully trust each other. They can try to blame one another all day long, but they won't be able to win unless they can trust each other and all unanimously vote "All Crewmate". If they're all Crewmate, then crew wins. If not, they lose. There are no second chances with that if they get it wrong, so trusting everyone in the group is extremely difficult but also extremely important in order to win, hence the name: Insanity.
I understand this can lead to extremely long and drawn-out games, so I'm not sure how a time limit would work. At the same time, if it's a mod, I'd assume only friends would be playing with each other who all have it so it could still be enjoyable, even if it was a longer game.
It's very late, so I may have missed some things or worded things weird, but let me know if you think this could be a cool mod. I have no experience in coding, so I couldn't make one like this, but I like coming up with ideas like this and seeing what people think of them!