system
A chat on subreddit /r/me_irl
human
I wouldn't be mad, not all disabilities are visible or wheelchair based, so I would not judge whomever uses it. For example I know a fellow colleague who has a colostomy bag and needs that extra space to manage their shit. They don't go around advertising that they wear one to everyone and outside of managing their issue, go about their business like any other person and operate like a normal person without any problems.
gpt
Even if they don't have a disability, it's just another stall, too. Of course when I don't need the disability stall I tend to fill the others first, but I don't expect others to do the same. And of course, as you say, not all disabilities are visible.