Another thing you could try is assign everything to seat1 and see if you can get just seat 1 to start:
99-multiseat.rules:
TAG=="seat", ENV{ID_SEAT}="seat1", TAG+="seat1" TAG=="seat", DEVPATH=="/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/*", TAG+="master-of-seat"
lightdm.conf:
[SeatDefaults] user-session=ubuntu greeter-session=unity-greeter user-authority-in-system-dir=true
[Seat:1] xdg-seat=seat1 xserver-command=/usr/bin/X -core -config xorg-seat1.conf -layout Seat1 -s 120 -isolateDevice PCI:2:0:0
Another thing you could try is assign everything to seat1 and see
if you can get just seat 1 to start:
99-multiseat.rules:
TAG=="seat", ENV{ID_ SEAT}=" seat1", TAG+="seat1" ="/devices/ pci0000: 00/0000: 00:1c.0/ 0000:02: 00.0/*" , TAG+="master- of-seat"
TAG=="seat", DEVPATH=
lightdm.conf:
[SeatDefaults] session= ubuntu session= unity-greeter authority- in-system- dir=true
user-
greeter-
user-
[Seat:1] command= /usr/bin/ X -core -config xorg-seat1.conf -layout Seat1 -s 120 -isolateDevice PCI:2:0:0
xdg-seat=seat1
xserver-