multiseat no longer works on nvidia nonfree, not a nvidia driver regression

I stupidly updated arch yesterday only to find that I couldn’t get my primary seat to log in. Fishing around, I found the primary GPU attached to the secondary seat(but still getting display on primary seat for the greeter; login would freeze most of the time, or take a very long time if it did work at all)
I assigned it back to the primary seat, and after that, multiseat stopped functioning entirely. The second seat can’t configure any displays and fails to create a session.

I tried downgrading nvidia drivers, flushing seats and reassigning, using a backup of the root directory(failed to boot with a large pile of errors) messing with xorg and lightdm configurators, changing greeters(lightdm-gtk-greeter in general just wouldn’t work on anything anymore), and eventually completely broke lightdm. Nothing made any kind of change to the secondary seat behavior however.

After that, I reinstalled fresh and tried again, confirming that multiseat no longer works on nonfree on the latest version(as of several hours before this post, the latest xfce iso available).
After that, I reinstalled from an older version, and attempted to install 450 drivers with the older lightdm, greeter, etc that came with it.(20.0.1?) However, after updating mhwd(I didn’t get any choice in that ofc) it failed to install 450 saying it was not available. Trying to install via pacman for any other branch just grabs 460xx on the latest revision. Tried installing bauh just to get discord up outside of a browser, and it fails to start until everything else is updated.

The regression isn’t in nvidia drivers this time, it’s in something else, but I can’t find any way to pick and choose the working packages and get my workstation up and running again. Good thing I didn’t update my servers, even though they’d probably be fine, with all the Intel Integrated, but this means I can no longer do my job until someone comes along and fixes a software issue.

Is arch just Windows 10 without the software compatibility now?

can you report

inxi -Fza
sudo mhwd-kernel -li
sudo ls /etc/mkinitcpio.d/*.preset
sudo journalctl -b0 -g lightdm

for win 10 , os-probe is desactived by default , if you need

`echo GRUB_DISABLE_OS_PROBER=false|sudo tee -a /etc/default/grub && sudo update-grub`
-- Journal begins at Tue 2021-04-27 12:37:02 PDT, ends at Tue 2021-04-27 15:12:45 PDT. --
Apr 27 15:10:19 Jellopocalypse audit[342]: AVC apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/lightdm/lightdm-guest-session" pid=342 comm="apparmor_parser"
Apr 27 15:10:19 Jellopocalypse audit[342]: AVC apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/lightdm/lightdm-guest-session//chromium" pid=342 comm="apparmor_parser"
Apr 27 15:10:19 Jellopocalypse kernel: audit: type=1400 audit(1619561419.112:10): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/lightdm/lightdm-guest-session" pid=342 comm="apparmor_parser"
Apr 27 15:10:19 Jellopocalypse audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj==unconfined msg='unit=lightdm comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
Apr 27 15:10:19 Jellopocalypse dbus-daemon[545]: [system] Activating via systemd: service name='org.freedesktop.Accounts' unit='accounts-daemon.service' requested by ':1.5' (uid=0 pid=590 comm="/usr/bin/lightdm ")
Apr 27 15:10:23 Jellopocalypse lightdm[1376]: pam_succeed_if(lightdm-autologin:auth): requirement "user ingroup autologin" was met by user "jellymouse"
Apr 27 15:10:23 Jellopocalypse audit[1376]: USER_AUTH pid=1376 uid=0 auid=4294967295 ses=4294967295 subj==unconfined msg='op=PAM:authentication grantors=pam_faillock,pam_shells,pam_permit,pam_gnome_keyring acct="jellymouse" exe="/usr/bin/lightdm" hostname=? addr=? terminal=:>
Apr 27 15:10:23 Jellopocalypse dbus-daemon[545]: [system] Activating via systemd: service name='org.freedesktop.home1' unit='dbus-org.freedesktop.home1.service' requested by ':1.13' (uid=0 pid=1376 comm="lightdm --session-child 12 15 ")
Apr 27 15:10:23 Jellopocalypse lightdm[1376]: pam_systemd_home(lightdm-autologin:account): systemd-homed is not available: Unit dbus-org.freedesktop.home1.service not found.
Apr 27 15:10:23 Jellopocalypse audit[1376]: USER_ACCT pid=1376 uid=0 auid=4294967295 ses=4294967295 subj==unconfined msg='op=PAM:accounting grantors=pam_access,pam_unix,pam_permit,pam_time acct="jellymouse" exe="/usr/bin/lightdm" hostname=? addr=? terminal=:0 res=success'
Apr 27 15:10:23 Jellopocalypse audit[1376]: CRED_ACQ pid=1376 uid=0 auid=4294967295 ses=4294967295 subj==unconfined msg='op=PAM:setcred grantors=pam_faillock,pam_shells,pam_permit,pam_gnome_keyring acct="jellymouse" exe="/usr/bin/lightdm" hostname=? addr=? terminal=:0 res=su>
Apr 27 15:10:23 Jellopocalypse lightdm[1376]: pam_unix(lightdm-autologin:session): session opened for user jellymouse(uid=1000) by (uid=0)
Apr 27 15:10:23 Jellopocalypse kernel: audit: type=1100 audit(1619561423.712:50): pid=1376 uid=0 auid=4294967295 ses=4294967295 subj==unconfined msg='op=PAM:authentication grantors=pam_faillock,pam_shells,pam_permit,pam_gnome_keyring acct="jellymouse" exe="/usr/bin/lightdm" >
Apr 27 15:10:23 Jellopocalypse kernel: audit: type=1101 audit(1619561423.712:51): pid=1376 uid=0 auid=4294967295 ses=4294967295 subj==unconfined msg='op=PAM:accounting grantors=pam_access,pam_unix,pam_permit,pam_time acct="jellymouse" exe="/usr/bin/lightdm" hostname=? addr=?>
Apr 27 15:10:23 Jellopocalypse kernel: audit: type=1103 audit(1619561423.712:52): pid=1376 uid=0 auid=4294967295 ses=4294967295 subj==unconfined msg='op=PAM:setcred grantors=pam_faillock,pam_shells,pam_permit,pam_gnome_keyring acct="jellymouse" exe="/usr/bin/lightdm" hostnam>
Apr 27 15:10:23 Jellopocalypse lightdm[1376]: pam_env(lightdm-autologin:session): deprecated reading of user environment enabled
Apr 27 15:10:23 Jellopocalypse audit[1376]: USER_START pid=1376 uid=0 auid=1000 ses=1 subj==unconfined msg='op=PAM:session_open grantors=pam_loginuid,pam_keyinit,pam_limits,pam_unix,pam_permit,pam_mail,pam_systemd,pam_env,pam_gnome_keyring acct="jellymouse" exe="/usr/bin/lig>
Apr 27 15:10:23 Jellopocalypse audit[1376]: USER_LOGIN pid=1376 uid=0 auid=1000 ses=1 subj==unconfined msg='op=login id=1000 exe="/usr/bin/lightdm" hostname=Jellopocalypse addr=? terminal=/dev/tty7 res=success'
Apr 27 15:12:45 Jellopocalypse dbus-daemon[545]: [system] Activating via systemd: service name='org.freedesktop.home1' unit='dbus-org.freedesktop.home1.service' requested by ':1.86' (uid=0 pid=16222 comm="sudo journalctl -b0 -g lightdm ")
Apr 27 15:12:45 Jellopocalypse sudo[16222]: jellymouse : TTY=pts/2 ; PWD=/mnt/Wyrm ; USER=root ; COMMAND=/usr/bin/journalctl -b0 -g lightdm
[jellymouse@Jellopocalypse Wyrm]$ sudo ls /etc/mkinitcpio.d/*preset
/etc/mkinitcpio.d/linux510.preset
[jellymouse@Jellopocalypse Wyrm]$ sudo mhwd-kernel -li
Currently running: 5.10.30-1-MANJARO (linux510)
The following kernels are installed in your system:
   * linux510
[jellymouse@Jellopocalypse Wyrm]$ inix -Fza
bash: inix: command not found
[jellymouse@Jellopocalypse Wyrm]$ 

Also, I have discovered that xsetwacom can no longer find my wacom tablet at all. --list devices returns nothing, and trying to set the binding area for any of it’s touch inputs returns “cannot find device”.
libwacom is up to date, wacom dkms is up to date, xf86-input-wacom is up to date, and wacom-utility can’t find a tablet.

Is there a working image of manjaro xfce with nvidia nonfree from like… 5 months ago?

KDE somehow detects the tablet still.