The Xteink 4 reader in my possession has been fantastic flashed with Crosspoint firmware. It's been so great that I'd like to gift these to my friends who enjoy reading. I'm very glad the ability to flash these is being preserved as a special offering from Xteink.
I'm really curious about it. It says 14 day battery time (based on typical reading (1–3 hours per day))? What does that mean? Surely when you don't touch it does not consume any battery, right?