To be able to adapt anything you need switch immobilizer to on in ECU EEPROM first.
It should not matter if your instrument cluster is IMMO2 or IMMO3 as long as your ECU is IMMO2 as IMMO3 clusters are backwards compatible (at least Volkswagen ones
).
Main issue I see is you are trying to pair TT (BAM) ECU with A4 cluster which might just not communicate properly. Perhaps it will work if you use different ECU EEPROM (but be sure to backup yours first) (one from APU or AWT engine) but it may also require to use flash from such ECU and tune it according to your setup.