Hi @bjudd and thanks for your query. Unfortunately, this is correct as Tobii will no longer support the Linux platform with the 4C.
If you want to develop a product integrating Tobii Eye Tracking we have other solutions such as the Tobii Eye Tracker 4L, and integration platforms that also support Linux and MacOS. If you are interested in integrating eye tracking in your product please Contact Tobii.
Apologies for any inconvenience and thanks for your understanding.