This malfunctioning behaviour doesn't seem that uncommon though. Here [1] is another story from 2016 with the same root cause.
I'd like to know how widespread that non-standard behaviour really is.
I could imagine that many small businesses, e.g. cafes, restaurants etc, use cheap consumer switches to manage their guest wifi. Those would seem to be vulnerable.
Another thing: Maybe this is nonsense, but couldn't you spoof PAUSE frames coming from another MAC address than your own, e.g. on wifi? If that's possible, you could disrupt service for selected other network participants even on well-functioning switches (provided you know the victim's MAC address).
[1] http://jeffq.com/blog/the-ethernet-pause-frame/
HN discussion: https://news.ycombinator.com/item?id=12339902