The ASUS ZenScreen MB166C is generally compatible with a Surface Book 2 and Windows 11, provided that the USB-C port of the Surface Book 2 supports DisplayPort Alternative Mode (DP Alt Mode). There are a few important points to note here:

1. USB-C port: make sure the USB-C port on your Surface Book 2 supports DP Alt Mode, as the ZenScreen MB166C has a USB-C port for both power and video transfer.
2. software and settings: Check that the display settings on your Surface Book 2 are configured correctly. This may mean checking the video input settings on the external display and making sure it is set to the correct port.
3. drivers and software: Make sure that all necessary drivers and software are updated on your Surface Book 2 to ensure a smooth connection.

If you follow these points, the ASUS ZenScreen MB166C should work smoothly with your Surface Book 2 and Windows 11.