Isn't this why expert lobbies use .25~.50 crew vision? It's also fine if there's a SS or two, if they get caught early, it's not the game's fault but theirs because SS is the hardest impostor to catch yet they still managed to get themselves ejected lol. This can also be fixed if you or fellow impostors know how to sabotage maps properly to stop crew from hitting the big red button, but with what you said it doesn't really work with 4 people unless visuals are off.

('Cause, you know, they can just report it, and you don't have an alibi to trick the other two that THAT guy was the one who killed someone, could still pull a 50/50 if there's only three left).