Cute, but I want to give a shoutout to

https://www.xteink.com/

Xteink already makes such devices, including the magnetic connection.

In addition to the the cool form factor, and the magnetic attachment, there's a whole host of custom, open source firmwares for it such a Papyrix, Crosspoint, or Crossink.

Boox steals Linux: https://en.wikipedia.org/wiki/Onyx_Boox#GPL_compliance

Would be nice if I could lock the screen somehow. Let's wait for more details...