Help with checking up on Psycho Ex Girlfriend?

Because of my experiences with Nerds Are Sexy and Even Evil Has Loved Ones, I have this instinct that Psycho Ex-Girlfriend use is NOT limited to "when hero's ex-girlfriend becomes a villain", but is often (perhaps majority of the time) used to mean "girlfriends who turn Yandere with any result for any reason."

I'd like to check this. I'll do my best to get as much done as I can myself, but if anyone comes across misuses, either individually or in patterns, do you mind terribly posting it here so I can save myself the effort of looking in those places?

Thanks!

Well people can be Yandere without ever being the person's girlfriend... Rejection is the main source of Yandere.

True, but hopefully, my meaning comes across. This just strikes me as one of those names that gets abused a lot, and I'd like help confirming/refuting.