Notification Mails: Links Point to "localhost" (And Setting xwiki.home Breaks the Annotation Feature)

I just stumbled accross

So the Wiki Descriptor can be edited without installing any optional Extension. However, do you - as the admin - have to know the URL how to get to this page, or is it somehow accessible / linked from the settings screens?

And second question - why do I have to configure the hostname and everything here if it also can be set (at least globally for the whole installation) in the config file? I only have a single wiki running on my instance.

This information looks somewhat redundant to me, and I wonder which of those I could leave empty - in case of future changes, it’s really easy to overlook one of the different places. (There’s xwiki.cfg, xwiki.properties, this “Wiki Descriptor”, the Apache reverse proxy config, …, and all refer to / repeat definitions of the same host name or URL fragments…)

In any case, the settings in the Xwiki descriptor seem to be wrong and I should probably adjust them, but they always have been wrong then… (The Page was last changed in Juni 2019 by superadmin, according to its header.)

This still does not solve the observation, that annotations work if I don’t eplicitly configure anything and break if I set the URL in xwiki.cfg…