I used the user_pkglist option on EndeavourOS installer installing Cosmic alone not on top of other Desktop.
Run this before starting Installer on the liveSession of EndavourOS ISO (from a terminal):
Make sure packages database is updated, as ISO is may created before cosmic was added to the repo:
sudo pacman -Sy
following with adding packages list:
With cosmic-greeter (greetd):
wget -qN --show-progress -O /home/liveuser/user_pkglist.txt https://raw.githubusercontent.com/EndeavourOS-Community-Editions/cosmic/main/user_pkglist.txt
And to change systemd services module to enable cosmic-greeter:
sudo wget -qN --show-progress -O /etc/calamares/modules/services-systemd.conf https://raw.githubusercontent.com/EndeavourOS-Community-Editions/cosmic/main/services-systemd.conf
Using SDDM as Login Manager (DM):
wget -qN --show-progress -O /home/liveuser/user_pkglist.txt https://raw.githubusercontent.com/EndeavourOS-Community-Editions/cosmic/main/user_pkglist-sddm.txt
And make sure to install online choosing no-desktop !
If GDM is used it comes with a minimal GNOME session so --- On first boot change session to cosmic: