Hi,

1.
In the manual 12.9.9 there are several desktop services mentioned

But cinnamon-desktop and kde plasma-desktop is not mentioned,
even though you can download the cinnamon and plasma-desktop packages.

Are the mentioned desktop services like Gnome, XFCE, MATE only examples
and cinnamon and plasma are not mentioned?
or is the cinnamon and plasma desktop not available/working yet,
even though the packages can be downloaded?

2.
You can download the desktop environment "XFCE 4.18.2"
Additionally there are many other XFCE packages available for download.

Are those additional packages completely separate packages
which I can additionally install?
or are some of them included in the  main "xfce 4.18.2" package?

How can I know which packages are included in the main xfce 4.18.2 
package? Which command tells me that?
in order not to install something twice?

Or is it no problem to install something twice, Guix will tell me that
and handle it.

Kind regards

Gottfried