I have two graphics cards in my machine:

00:02.0 VGA compatible controller: Intel Corporation RocketLake-S GT1 [UHD Graphics 730] (rev 04)

02:00.0 VGA compatible controller: NVIDIA Corporation GK107 [GeForce GT 1030] (rev a1)

Then I have three monitors. The Nvidia card has both DVI and HDMI outputs.
The Intel has HDMI and Display Port.

I connected two Lenovo displays to the Nvidia, and an NEC to the Intel.

I do NOT want to use xinerama. Why? Because when it lets windows drag from screen to screen, which I do not want. I want each monitor to be its own display.

I am a long time Zaphod mode user, and I have come to love it.

So just what kind of config whizzeroodery do I need to do to get a dual seat, three
headed configuration? I have two keyboards, and two mice?

Working xorg.conf please!

I tried using loginctl, and I tried using xdm, and evilwm.
I had to login using termux from my cellphone to kill the xdm X sessions to get control of my computer back.