Relax permissions for faster migration of old documentation pages

Problem/Motivation

After clicking the "migrate this documentation" link in a doc page from the old doc system (see #3442232: Decide what to with TO BE MIGRATED → ) this text is shown:

You can only migrate pages into the guide you maintain. To create a guide for your project, edit the project page and follow the links on the "Project documentation" tab.

These are the guides I maintain, probably because I created them: Boost, Bootstrap5, Chaos Tool Suite (ctools), Geofield, Leaflet, Matomo Analytics, Open ReadSpeaker, and since I don't maintain for example "Administering a Drupal site" it's not an option for me to migrate it there ...

Proposed resolution

Requiring the creation of a new guide can lead to overly convoluted page structures, and (simply) pages not being placed where they belong.

Would it be possible to allow users to migrate a page from the old system into existing guides, that they don't maintain?

So -- in other words -- under "Documentation guide to migrate page(s) into: *" all guides would be listed, also general docs?

I understand that there may be good reasons for the limitation, to keep things under control, and not getting an existing guide flooded with pages .... but relaxing the permissions could help get the pages migrated faster.

Remaining tasks

Decide if relaxing permissions for migrating doc pages to any guide is possible.