Only a few:
C version support connects mechanical doorbell, this is the only hardware change
Support AP mode
You can install the latest firmware with the C version, for the best compatibility and stability
In settings, did you change Access Control - RS485 - Peripheral Type to Card reader and Access Controller respectively?
For the reader Minmoe, set the peripherals type as Access Controller, and set the RS485 address to 2, Output Type: Person ID.
For the controller Minmoe, set the peripherals...