@jonah, thanks for posting. I'm the guy that wrote those PDFs. The #1 thing that suprised me in doing the research is that the standard 911 system as defined by the FCC does not get the caller's coordinates from their cell phone like Uber does.
Now with that said, there are a lot of 911 call centers that use RapidSOS or other add on technology that do get the caller's coordinates directly from the caller's phone.
Of course a person calling 911 has no way to know beforehand whether the 911 call center handling their call will be able to get their coordinates via technology. That is the reason I urge everyone to have some way to use their phone to get their coordinates and the equally important accuracy value. Use a compass app, use FindMeSAR (I am developer) or use something else. I don't care. Instead, the important point is that you use 'something instead of nothing'.
I am the developer of FindMeSAR (https://findmesar.com) which is mentioned here in the comments. The first time you open this web page your device must be online. The code is saved in a special part of your browser's memory. This web page (aka web app) will then work offline. This is done with service worker coding plus appcache coding as a fall back.
If you are a bit skeptical that a web page can work offline, just go ahead and try it.
There is an icon you can save on your screen and a 'Tips' button with more information.
Finally, it turns out that if you ever need to call for help with your cell phone there are some things you should know in order to have the best chance of reaching 911 or anyone else. After reading through a whole pile of documents on the FCC website I put my findings into 4 PDF reports. The end of each report has links to the other reports.
Now with that said, there are a lot of 911 call centers that use RapidSOS or other add on technology that do get the caller's coordinates directly from the caller's phone.
Of course a person calling 911 has no way to know beforehand whether the 911 call center handling their call will be able to get their coordinates via technology. That is the reason I urge everyone to have some way to use their phone to get their coordinates and the equally important accuracy value. Use a compass app, use FindMeSAR (I am developer) or use something else. I don't care. Instead, the important point is that you use 'something instead of nothing'.