The emergency note can be readable only via WeExpire, and that's for security reasons - you always need to be notified that someone is trying to access your emergency note.

As any other platform WeExpire could temporarily go down, but it will be always back online before than the minimum inactivity time you can set up in your emergency note (1 day).

Yeah, but platforms fail, go out of business and can have issues.

If you use this service (or any other of the ones mentioned in the other comments) you'll need to periodically check that they are ok (and that all your details are up to date).