[LightDM] remote xserver

[Alan Greenberger]

I have lightdm 1.26.0-4 installed on debian 10.6 Buster.
No matter what I do, lightdm runs on the local machine:
/usr/lib/xorg/Xorg :0 -seat seat0 -auth /var/run/lightdm/root/:0 
-nolisten tcp
vt7 -novtswtch

I had a line in /etc/inittab:
y:5:respawn:/sbin/getty -n -l /root/choosehost.sh 38400 tty7
to call a choosehost.sh script that could let me choose:
/uxr/bin/X vt7 -once -listen tcp -query $host -ac
This doesn't get run.  It used to work in an older version of debian without
lightdm.

Then I tried two lines in /etc/lightdm/lightdm.conf:
xserver-command=/usr/bin/X vt7 -once -listen tcp -query Thehostname -ac
xserver-allow-tcp=true
This is ignored, just runs the local Xorg above.

I added /etc/lightdm/Xsession with:
#! /bin/bash
/usr/bin/X11 vt7 -once -listen tcp -query Thehostname -ac
No Effect!

Is there any way to get this to work with lightdm?