Sony Mobile has released a new firmware update for the Xperia X Concept program in the form of build number 38.3.1.A.0.32C. This new update introduces Glove mode, which you can access via the shortcuts. The other big addition, is better audio functionality with LDAC support.
Other changes include Google security patches update to 5 February 2017, a new version of the camera (with more options in manual mode) and memory performance improvements. Sony has had to temporarily drop VoLTE support due to issues on German networks, but it should be fixed soon. Overall, another worthwhile update from the Sony Xperia Concept team.
Update: Sony has now made its discussions on the Concept firmware available to those outside of the program – you can follow its progress here.