Just took a quick look, thanks, I'll look into it more closely. It seems to depend on Adafruit's BLE sniffer device (https://www.adafruit.com/product/2269
), which has custom firmware that is probably not reproducible on either the on board chip or a standard USB dongle. I've used that device on a PC, not a Pi, so I appreciate the link. But again, programming the firmware on a standard adapter... That is going to be rough (impossible).
Oh, and you might be surprised by what you can learn with gatttool and hcidump.