Edwiser Solution offers a custom fields feature, and the fields are synced with the Moodle platform as well. However, the fields can only be added to the WooCommerce checkout page and not the registration page. Sharing documentation for your reference to configure the same,
This feature is part of Edwiser Bridge's latest update where they can sync user's first name, last name and password from Moodle to WordPress. screenshot-staging.edwiser.org-2021.07.20-14_57_22.png
If you want to create users that existed in Moodle before the implementation of the Edwiser Bridge plugin then you can make use of the Edwiser Bridge PRO feature where it lets you sync Moodle users from Moodle to WordPress.
Looks like your last update tonight to 3.9.3 improved it. However, the editor still seems very right aligned and loses width as a result. This also requires me scroll horizontally inside the editor, which I did not have to do before the update. See screenshot attached.