And an update to the randomly connecting TFT/battery flattening issue on my sons GSA.
Following the first diagnosis and "repair". Within two weeks the damn thing started doing the same again.
Bike back to BMW, son supplied with a loan Mini for two weeks.
Collected the bike, and, you've guessed it. The same day, the same thing again, bike randomly illuminates the TFT and flattens the battery.
Son now on a loan 1250GS whilst the dealership re-evaluate the issue.