Hi @meide, thanks for your query. I am afraid that monocular calibration is not supported by any of the consumer levels eye trackers such as the EyeX or 4C and so this feature is more a question of the eye tracker model itself rather than the particular SDK you are using.
In terms of other devices within the Tobii Pro range that may support monocular calibration, I would suggest to be sure that you ask Tobii Pro Support directly @ https://www.tobiipro.com/contact/support/
If you have any further questions, please don’t hesitate to let us know.