We only use the normal login page so if there is an issue here it is in the mediawiki login form (e.g. it doesn't load JavaScript with the right target)

Let me know if there is anything specific you need done in the extension!

The only thing that looks suspicious is that you're using the UserLoginForm and UserCreateForm hooks. These hooks are deprecated under AuthManager, so it would be good to move away from using them.

All those hooks do is add an image to the top of the form. This is important as it gives context to where you are logging in.

<div class="watermark"><img src="$1"></div>
where $1 is the value of $wgMobileFrontendLogo

If you are deprecating these, you need to provide a new way to add that image. I consider that a blocker to rolling this out.

Change 288334 had a related patch set uploaded (by Gergő Tisza):
Update for AuthManager

https://gerrit.wikimedia.org/r/288334

Change 288334 merged by jenkins-bot:
Update for AuthManager

https://gerrit.wikimedia.org/r/288334

Change 296508 had a related patch set uploaded (by Gergő Tisza):
Update for AuthManager

https://gerrit.wikimedia.org/r/296508

Change 296508 merged by jenkins-bot:
Update for AuthManager

https://gerrit.wikimedia.org/r/296508