Please note the monorpice cadet printer is a rebranded version of these printers and the provided configuration should work.
You can add wifi support using ESP3D. Basically connect your own NodeMCU to second serial port of the MCU. See ESP3D wiki for connection diagram.
In Marlin configuration.h set:
#define SERIAL_PORT_2 3
Examples provided here have not been tested with wifi board from manufacturer.
Setting #define SERIAL_PORT_2 3
in Marlin configuration.h might be enough to work with manufacturer wifi board.
Feedback are welcome.