I have this device with root access and if anyone wants data for adding openwrt support I would be happy to assist. I personally have no experience with kernel and driver development.
Running the latest firmware 1.0.77
We have a thread about this at 4pda with some additional info https://4pda.to/forum/index.php?showtopic=1059931&st=40
BTW I don't see it referred to as AX10000, it's usually called XIAOMI Router 10000 or XIAOMI Router 10 Gigabit, the model number is RC01.