I've yet to see UPnP work...

I was surprised as well as it's something I turn off on devices I control and I haven't really assumed it was a thing. But recently at a friends house I decided to install upnpc on my Linux laptop and give this a try:

| upnpc -a 192.x.x.x 8080 80 tcp

And to my surprise it just worked. This friend just upgraded to fiber and had just received a new router.