I need artix-archlinux-support but not the universe junk.
What is forcing you to install anything else from the universe repo? Artix-archlinux-support is not necessary for running an Artix system, so I doubt it will moved back to galaxy.
1. Enable the Universe repo in /etc/pacman.conf
2. Install what you need
3. Comment out the Universe repo in /etc/pacman.conf
Be careful about what you mix and match from the Arch repos with Artix. You may get into dependency issues faster than you can imagine.
I wouldn't recommend that since you will run into problems when artix-archlinux-support package gets updated and you will not receive any updates.
archlinux-keyring, archlinux-mirrorlist, etc. can't be added to the official repos because it interferes with the building of our own packages. Surprise systemd dependencies (which do happen from time to time) can go unnoticed because those packages will just pickup the archlinux-support and generally build successfully.
Then renable it, update what you need, and disable it again. Think of the activity as a lightswitch.