the overton window aka “the window of discourse” is literally about talking, and making things more acceptable by their existence in the public consciousness

the more people TALK about alternative voting mechanisms, the more likely it is for some change to occur… 1 person can’t just up and change the system overnight, but by “signalling” as you’ve dismissively called it, it makes it more likely that other people talk about it and that makes it more likely that it becomes policy