Hi @mattbarb, thanks for your query.
A number of third party tools exist to analyse raw 2D gaze data into fixations, however as your case is within XR SDK, then we would refer you to the following repository:
Which takes as input a Dataframe with seven columns: One is the time; three are the position of the gaze; three are the position of the subject’s head.
Hopefully you still have access to the raw data of the project? It would be great if you would also care to share your project code, either on github or as a ZIP file.