Update to the above:
Activating these 2 adaptations makes the lane assist and adaptive lane guidance appear correctly in the car driver assist menu, then you can play between the drunk driving mode and the very nicely working active mode, AND you get to select from the three different warning levels. Selecting "low" lets you rest your hands for about 20 seconds before the car guides you to take over the steering.
Address 5F,5G0 035 869 ,channel ENG122227-ENG117506-Car_Function_Adaptations_Gen2-menu_display_Lane_Departure_Warning,adapted from,not activated ,to,activated
Address 5F,5G0 035 869 ,channel ENG122227-ENG117508-Car_Function_Adaptations_Gen2-menu_display_Lane_Departure_Warning_over_threshold_high,adapted from,not activated ,to,activated
And the A5 adaptation:
IDE10873- personalization,not activated ,1 <--- This indeed was not activated.