I have been with my Boox Max 3 for a few weeks now.
It's working as expected for an e-ink monitor except that I'm having a strange bug:
Every few minutes, the screen freezes for a few seconds and then it "un-freezes". A few minutes later, it freezes again for a few seconds, then unfreezes etc...
It's the screen which freezes, not the PC, since I've tried to perform some actions blindly when it was frozen and they were executed.
I'm on Linux 5.3.12, with proprietary Nvidia driver (I've tried opensource Nouveau driver but I didn't get the screen recognized).
Are you experiencing this also??