In the UK, our national mapping service has built a tool for hosting vernacular place names to help first responders.

https://www.ordnancesurvey.co.uk/news/new-national-vernacula...

That's neat, thanks for sharing! We had the ability to accept a what3word location however it was a really convoluted process to actually attempt to use it. Unfortunately I never personally had anyone use it to give a location, even though it probably would have helped in many cases.

Had some calls where people would be hurt in a forest on a trail system and it was pretty common for people to not even know the name of the trail they are on nor which street they entered it from. Sometimes the GPS location the phone provided to EMS would help, but it also wasn't always 100% reliable, especially if they were in a forest. So being able to have them look at a map on their phone, pin where they are, and give a what3word location would have been immensely helpful.

The kind of system you linked to would also have been quite helpful for the other problems I mentioned.