IncusOS ignores anything under the state property when sent back via the API. You need to submit changes using the config property:
config:
pools:
- name: local
type: zfs-raid1
devices:
- /dev/disk/by-id/nvme-SAMSUNG_MZQLB960HAJR-00007_S437NA0MB00607-part11
- /dev/disk/by-id/nvme-SAMSUNG_MZQLB960HAJR-00007_S437NA0MB00139