it is currently possible to define that two elements are on the same unit of a rack. However, what about when I have three elements? Indeed, we have a mobile rack which is equipped with video equipment which has 3 elements per unit of height.

Would it be possible to add this additional option?

Give a user/profile the rights to change "Sub-entities" to "Yes" or "No", even if the user doesn't have recursive permission.

When I add a rack in GLPI it assumes U1 is the bottom-most U. On my rack U1 is the top-most U. It would be nice if this was configurable for racks

When merging tickets, I think it could be useful to have a check box that, if flagged, could stop the sending of an email to all actors in the new merged ticket.

Thanks. 

The maintenance mode would be much more useful if it could be scheduled, showing a message to all users after login letting them know about the maintenance's date, time and (expected) duration, as well as a customizable message.

When we hover a requester in ticket, a card appears.

The idea is to add a link/buton that will call the requester in MS Teams.

Maybe by adding a specific field in user profil that will be sync with Active Directory.

When creating a new user, it's showing the "Last Name" and "First Name" fields into USA format.

In my country (Brazil), it's more common we fill the First name and the Last name after.

Into my User preferences and at Global preferences, we'd set the Display order of lastnames firstnames (Ordem de exibição de sobrenomes e nomes) to "First Name, Last Name" (Primeiro nome, Sobrenome).

It would be great if GLPI also reflect this preference at it's forms.

Would be very useful to have a Table of Content in each knowledge base article.

The TOC TinyMCE plugin turn each heading in a summary topic.

https://www.tiny.cloud/docs/plugins/opensource/toc/

When you click the icon to add a followup, the form is displayed but it does not have the focus

you need to click it to start writing ...

would be nice to set focus on the form

Please consider moving the cartridges to the location of the warehouse location. Deleting from one object and adding to another object is very difficult.

Do the move action:

Also, the history of adding and removing cartridges is not recorded in the history. An unscrupulous administrator can delete it and not track it in any way. (there is a possibility that he will be able to take the cartridges for personal purposes).
If it is possible to implement the process of notifying the Super-Admin about the action of technical personnel over cartridges.