I am sure that the experimental labels that are accessible with a new generation Interface will reveal what Hex 10 does mean in the camera coding.OK Finally got to the end of this and am surprised others didn't trip over the same issue. To recap, my lane assist required me to fit the image processing module but the camera was already in the car for matrix beam. After completing the install the lane assist indicator sometimes flickered and the MMI showed Lane Assist not Active Lane Assist and also regularly went to grey (unavailable).
The problem was the camera coding which within VCDS has a dropdown box to select lane assist. If you use the shortcut to enable or disable lane assist it will set byte 0 bits 0 and 1 either to 00 (not installed) or 01 (installed). However by looking at a number of other cars including my own A8 these cars had a bit setting of 10 which is not a configurable option within VCDS. Have chosen this setting and removing all my other efforts Lane Assist is now fully working. I hope this helps someone, took me a month to resolve. Done with retrofits for a bit having had a similar nightmare with Kessy, will do another post on that one outcome successful.