I run a private wiki for my company.
Mediawiki version is 1.31.1
Auth_remoteuser is 2.0.1 (c7daa32) 21:57, 11 November 2019
We also run Lockdown ( – (381da77) 16:35, 1 December 2018) to make part of the pages private.

Auth_remoteuser is configured to use a server variable set by our SSO implementation and then via mapping translated to a wiki login for readability. Account creation is disabled and done manually. This works like a charm.

However, today I ran into an issue, when you click on an image a user was not able to upload a new version of a file. When looking better, I noticed that top right there was a log-in button so it seems you are not logged in when looking at a file. We don't use a remote repository, just locally uploaded files.