I might not have been clear enough. We are already using the Gaze SDK, since we found out about the limit of one tracker for the EyeX engine.
This might just be a misunderstanding.
According to a recent blog post of yours (http://developer.tobii.com/new-gaze-sdk-packages-tools-run-tobii-rex-linux-android/), the Gaze API is no longer supposed to handle screen setup. Since I had yet to find this functionality in the new SDK, I was worried and started to search for it under the name it used to have, XConfig.
Since I found nothing, and came here for clarification on what to do, but after a closer inspection, I now found tobiigaze_set_display_area which might be what I was actually looking for.
Sorry for any misunderstandings from my part.