Some of Xteink’s credit card-sized e-readers are losing their best feature

Xteink is disabling the third-party firmware flashing function on its X3 and X4 credit card-sized e-readers. The company cited concerns that third-party firmware caused poor optimization, crashes, and screen damage on some devices, and that users who reverted to official firmware faced issues with reading records and connectivity. The restriction applies to newly shipped devices, though existing owners retain access.