Please do not support Onyx or buy any Boox tablets! I'm reproducing an earlier comment[0] below:
They're a lousy company that does not respect the GPL and ships intentionally insecure software (ancient linux kernel with SELinux disabled for starters) that phones home to Chinese servers. The bootloader is locked, so putting pmOS is out of the question and their update files are intentionally obfuscated.
This received some attention in the re--it community last month--the company still does not care [1]. It's a tragedy because their hardware is good, otherwise and they can compete on that.
In other news, I am now a happy owner of a ReMarkable 2 and the first day I was able to SSH in, set up rsync on my local network and customize the hosts file to disable their cloud services. We should not tolerate the inability to run software on computers that we own, especially for devices that are as trusted as notebooks and personal computers, which this tablet is.
I'm not sure if I should sell my Boox Note or relegate it to use as signage. The only problem is that if the battery dies, it refreshes the display to a "battery depleted" screen, instead of leaving up the last image. But you can't customize that because the bootloader is locked.
Edit: Another note about Onyx. At least my Note does not support proper C2C charging. In other words, you can't charge from a Type-C charger, you have to use a type-A charger. My rM2 works just fine with all of my C2C chargers.