How to install on Akitio Mycloud mini (oxnas)?

It appears that this device never actually had stable support. The current trunk image hangs at:

Starting kernel ...

With no other output on console and appear hung even after 15 minutes. Both 22.02.0rc3 and 19.07.7 hang at the same location as the above message indicates. 18.06.9 actually boots! But it has issues:

    3.526064] oxnas-dwmac 40400000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
[    3.534515] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
- failsafe button reset was pressed -
- failsafe -
[    5.701173] urandom_read: 3 callbacks suppressed
[    5.701186] random: dropbearkey: uninitialized urandom read (32 bytes read)
Generating key, [    5.714859] random: dropbearkey: uninitialized urandom read (32 bytes read)
this may take a while...
[    5.963230] random: dropbearkey: uninitialized urandom read (32 bytes read)
Public key portion is:
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQCApfn48izIsCOFJsDlUQsTgu/wyS70qF6TdYlSHxDXGxasXZ0ZTV5+KpBRZs2jGP+QZgskAUDXWarJC1hLOKZ/aqjNjd0KMoT9YSVQ0rWJVE7yOBc84kNa+FP14Nq4VlG1SdcevzCslqodxM/hpzmZNMOAiL7U0uxzrACxFv0gUw== root@(none)
Fingerprint: sha1!! 7e:72:99:47:29:02:2d:02:7c:15:0f:25:99:f4:55:34:aa:5c:82:e3


BusyBox v1.28.4 () built-in shell (ash)

ash: can't access tty; job control turned off
  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 OpenWrt 18.06.9, r8077-7cbbab7246
 -----------------------------------------------------
================= FAILSAFE MODE active ================
special commands:
* firstboot          reset settings to factory defaults
* mount_root     mount root-partition with config files

after mount_root:
* passwd                         change root's password
* /etc/config               directory with config files

for more help see:
https://openwrt.org/docs/guide-user/troubleshooting/
- root_password_reset
=======================================================

root@(none):/#

Note that it is in failsafe mode even though no buttons were activated. Copying the ubifs-sysupgrade.tar file to /tmp and doing a sysupgrade then results in a system that boots with no network access!