Probably best to stop all the systemd units and then manually run “lxd --debug --group lxd” in a terminal, you can wrap that one with your ksm script.
Trying to wrap /etc/init.d/lxd with your script won’t work because just like “lxc”, the init scripts call “systemctl” which then talks to systemd over dbus, so the script isn’t itself the one spawning the process.