Thank you for contacting us about your query.
We are aware of the pixy2, and we would like to make it clear that we are very much for teams that are pushing the technology boundaries for the challenges and trying out new ideas and solutions.
So as far as I am concerned there wouldn't be problems using the camera, if you can clearly show that the line following algorithm has been written by the team members. This shouldn't be a problem.
However I also acknowledge that there is a fine line between own algorithm, modification, and copying. From my point of view, if you are taking something that is already made and modifying it in a certain way knowing the limitation and advantages, that is perfectly fine (but I'll see what other TC members think and come back to you). At the end of the day every technology is build on top of something and the point at which we set the base line is completely arbitrary.
What we don't want is when teams blindly use something, treating is as a blackbox; given that RCJ has education at its backbone, and I'm sure that's not your intention.