Actually did some digging and MXLinux draws systemd from the debian repositories, I don't actually have access to it through either the MXLinux or AntiX repositories, so if you keep debian repositories off your system those "hooks" should be directed to devuan repositories...  I think, please correct me if I'm wrong.

Cheers

Yes it is possible, How I would do it is add the mx17 repository, then pin the kernel and headers you're interested in.

Try adding the one you want to /etc/apt/sources.list.d/:

deb http://iso.mxrepo.com/mx/repo/ stretch main non-free
deb http://iso.mxrepo.com/mx/testrepo/ stretch test

then:

wget -qO -  http://teharris.net/mx17repo.asc | sudo apt-key add - 

Then pin in /etc/apt/preferences.d/:

Package: *
Pin: origin "mxrepo.com"
Pin-Priority: 100

I personally have the full mxrepos for all their tools, I pin the repository around 100, and usally have their testing commented out and use devuan backports...  If you want to use mx repos fully then you may also want to list antiX repos...  well good luck, I hope this helps.

So add mx17 repos and just install the packages you want

Edit: I edited pin priority to 100

Hi, I'd like to share my experience and solution, I had great difficulties with SDDM power buttons.  I tried all the solutions above, goofed around with sddm.conf files, grub files, etc... I thought I'd try lightdm and even had difficulty with lightdm not working with elogind but it did work with consolekit.

Anyway If you want to keep SDDM and elogind try

apt install openrc

I think the parallel loading of openrc solved any init order issues that may be causing the problem.