Hello again! The wiring is one issue (can't say for sure if it works with the expansion per se cause I have another breakout of the chip for testing purposes). Though, you can easily adapt this example -> https://www.element14.com/community/community/raspberry-pi/blog/2012/12/14/nfc-on-raspberrypi-with-pn532-py532lib-and-i2c and use I2C. Lastly, there is no official documentation regarding the schematics of the NFC/RFID expansion but our tests showed that that onion has left out SPI/I2C support for their chip -sth that needs to be checked. We are using python tools for now but I will get back to you if we find anything else!