I’m not aware of anyone using a Pixy2 with Python on a roboRIO, but it probably wouldn’t be too difficult to get libpixyusb2 running to talk to it over USB either.
That does seem like the ultimate best way to go, as then you should be able to get video in addition to the list of identified objects. As a hardware guy, SPI is more familiar to me than cross-compiling for the roboRIO, so maybe libpixyusb2 will be a second phase.