Change 618734 had a related patch set uploaded (by Majavah; owner: Majavah):
[mediawiki/extensions/CentralAuth@master] [WIP] Create special page to allow manually creating local accounts for global accounts

https://gerrit.wikimedia.org/r/618734

This would be helpful. Stewards will often create a global account, or the user may create their account and start editing on another project, but then is unable to edit English Wikipedia (or another project) that has their IP/IP range account-creation blocked for valid local reasons. It's particularly problematic if the user has already edited on other projects, because their accounts will then be split, leaving them open to allegations of inappropriate sockpuppetry.

It would be reasonable to limit this ability to stewards and local checkusers, because in many cases the users will also require IPBE to edit on that project.

In T259721#6449569, @Risker wrote:

[...]
It would be reasonable to limit this ability to stewards and local checkusers, because in many cases the users will also require IPBE to edit on that project.

The patch as-is will grant the ability to autocreate a local account to all administrators (in line with granting IPBE, which is also allowed to all sysops), via the Special:CreateLocalAccount page. If enwiki wants to make this CU-only ability, it's perfectly possible, you would just need to follow https://meta.wikimedia.org/wiki/Requesting_wiki_configuration_changes and create a Phab task with local consensus.

Added to Tech/News in https://meta.wikimedia.org/w/index.php?title=Tech%2FNews%2F2020%2F45&type=revision&diff=20593649&oldid=20593311

Change 618734 merged by jenkins-bot:
[mediawiki/extensions/CentralAuth@master] Create special page to allow manually creating local accounts for global users

https://gerrit.wikimedia.org/r/618734