Multiseat support, running weston on 2 different seats.

I have a setup with 2 GPU connected to 2 displays, 2 keyboard and 2 mouse. I have created 2 seats (seat0 and seat1) each with 1 keyboard, mouse, display and GPU using loginctl commands like below

"loginctl attach seat1 /sys/devices/pci0000:00/0000:00:04.0/0000:02:00.0/drm/card1"

And i am able to run Xserver on the 2 seats parallelly.

While running weston from tty when i pass seat1 in command line argument, i see issue "Operation not permitted" from loginctl when trying to open /dev/dri/card1

_[libseat/backend/seatd.c:80] Could not connect to socket /run/seatd.sock: No such file or directory
[15:18:48.659] [libseat/libseat.c:76] Backend 'seatd' failed to open seat, skipping
[15:18:48.663] [libseat/libseat.c:73] Seat opened with backend 'logind'
[15:18:48.663] libseat: session control granted
[15:18:48.665]
 file name : /dev/dri/card1[15:18:48.665] [libseat/backend/logind.c:131] Could not take device: Operation not permitted
[15:18:48.665] libseat open device returns: -1[15:18:48.665]
 fd<0[15:18:48.666] no drm device found
[15:18:48.737] fatal: failed to create compositor backend_

Few more observations

1. No issues with running weston on seat0.
2. Even if i do reverse assignment of cards i.e. card1 is on seat0 it works fine.
3. both cards have same permission.

So this might not be a weston issue but i need some help to understand the root cause