Left Cluster
Daytime Running Light - 3SL VRB36
Right Cluster
Daytime Running Light - 2SL VLB22
These are the channels you need for the DRL's. This is for UK Vehicles, Right hand drive. I am not sure if the adaptations change when the vehicle is Left Hand Drive, Although I imagine not. So looking at channel 2.
Theres no way to adapt it as such to only work with ignition on, That would be a wire/power supply job not adaptations, however you can change the operation of the DRL, Say instead of being a DRL, To have it come on only when the headlights are on. To do this, It would simply be a case of 09 Central Electrics -> Adaptation -> Leuchte2SL VLB22 -> Light Function A2 from Tagfahrlicht to Abblendlicht Rechts. Essentially tells the module to tell on with the right low beam, not the "DRL".
Now, There are 3 extra channels in the adaptation, Type Of Load 2, Lampendefektbit Position 2 and Fehlerort mittleres Byte DTC-DFCC 2. PERHAPS these may help in your quest to stop flickering from occuring, but i have no idea what the last two truly do. Do so at your own risk, and take backups!
Type of Load 2 is most likely to hold your answers - This tells the car what type of lamp it is. Xenon, Halogen, LED, Wattage, Etc. Maybe by attempting to tell it its a different type of LED lamp, this will fix the issue. Again, Do so at your own risk.
I hope this helps you in your quest, it does sound truly annoying!