Since the release of Obsidian, every new microupdate changed significant CSS classes in the Skins, which required our custom skin to be edited each time. However there is no way to deploy the new versions automatically.

My suggestion: Implement a way for Skins to be auto-updated.
The meta.xml-File in the skin could contain a new field like "official_url", which is then regularily checked for a newer version, than the one currently installed.

The list of scheduled tasks already contains the arguments of php scripts, while they are missing information in the asynchronous progress bar.
Tasks started at the same time, which differ in the arguments of the same script, are indifferent from each other.

When on the domain view and everything is ordered alphabetically, it would be better if the subdomains be grouped under the main domain (in alphabetical order) or even have an indentation to indicate they are a subdomain.

In Plesk Obsidian there are only 2 color options available.
More color options would be much more useful like Onyx has.

Currently in Tools & Settings > Branding it is possible to change logo for both: login page and top-left corner.
It would be nice to make the feature more flexible: separate logo change for login page and for top-left corner

Please make "My Extensions" the default when I click on Extensions. After the server is set up, I don't ever need the Catalog.

Add warning about domains that would be unavailable for management from Plesk when installing Web Admin key instead of Web Host or Web Pro.

Current warnings at License Management don't cover this:
Warning: Resellers management is turned off but you have several resellers(1).

OR

Warning: Customers management is turned off but you have several customers(1).

Now the customer's have to follow this guide:

https://support.plesk.com/hc/en-us/articles/115001047665

p.s.: based on a comment to this article.

For Plesk with non-English default language (Vietnamese, for example), notifications' content is still in English.

It would be useful to to get separate mails (copies) for each notification. For example to be able just to forward this notification to customer.

Currently, Website Preview on the domain name is using the domain certificate, which raises certificate warnings in web browser.
For previewed domains, which does not have the certificate defined, the default server certificate is used.
However, even if the wildcard certificate for the domain name on which websites are previewed is used as a default one, it still does not cover the resulting URLs on which websites are previewed.
That raises SSL warnings issue for new domains, which redirect to HTTPS according to settings in Plesk or website code itself.

Ability to declare an Alias of multiple IP address and use it to allow access through the Firewall.

I.e. I have several "management IP" and I want to allow access to Plesk Panel, Plesk Installer and SSH to them only.
It will be easier to declare who they are one time only and, in future, update them in one place as well.

Add a possibility setting up SmarterMail via command-line interface to allow server administrators to perform mailserver setup faster and automate.

Add possibility resellers/customers manage their own blacklists/whitelists. This feature will increase flexibility security settings.

It would be nice to have possibility to add comment/note to a service plan.
Since plans have to be created for every reseller, it would be nice to have something that could signal that it is the same plan on another reseller.

I use magic spam pro as plugin and it shows underneath the system information on the start page. That means if I want to start the plugin, I have to scroll down because the system info takes quite a bit of space. It would be nice to be able to customize the appearance of the start page / dashboard, i.e. what information is displayed and where.

To let the extensions log/note the actions in the Plesk's action log.

As of now, on any extension, a user can do any action without acknowledgment of what has been done.

For security purposes, it is desired to know what actions has been done in Plesk, and installed extensions.

We need to place a custom button in the Right Sidebar menu in the Customer interface, however, this option is not available in Tools & Settings > Custom Buttons > Add Link Service > Location drop-down menu selection.

As for now, this location is only available with a custom extension: https://docs.plesk.com/en-US/obsidian/extensions-guide/plesk-features-available-for-extensions/implement-ui/integrate-to-plesk-ui/add-custom-buttons.73624/

Please add a possibility to show both IPv4 and IPv6 on the Plesk Home page inside the System Overview section, if there is a configured IPv6 address on the server.