The Plesk Joomla Toolkit
The current version is still a bit slow and does not offer any options to e.g. create single Plugins and templates, but it does offer a way to determine the current version and see if there are Updates there.
If you use Joomla correctly, you probably use more extensive maintenance software, but this toolkit is suitable for beginners, or offers the reseller or Administrator a good overview of the installed Joomla instances and can help customers to Update to your side.
The Joomla Toolkit Dashboard
About the Dashboard of the Joomla installation you can now log directly into the backend, edit files with the File Explorer, or the Database directly in phpMyAdmin edit. So it saves a few Clicks in the Plesk surface.
On the right hand side there is information about the installed extensions, database information and the configuration entries.
At present, this does not have any real benefit. With the WordPress Toolkit there are much better setting options so that you can use a defective Plugin can deactivate this via Plesk and then log in normally.
This Functions will hopefully be added. Then you can have your Joomla updated with Plesk.
However, experience has shown that at least one Backup necessary, because in many cases Joomla can be made unusable with an update.