Sorry about all the trouble those crazy cats caused
Glad you passed despite the engine light.
By the way you already have top quality spacers on those rear labmbdas.
So I guess the next step is either get a VCDS cable so you can re-set the light yourself, or pay MRC Tuning to code out the error code. They don't remove the rear lambdas for some reason, I guess it would require a more major re-code because they are looked for during the start-up routine. Maybe they can do that but that may cost more money, then you can ditch those lambdas completely.
You have these ones, Wayne Angle blocks
https://www.audiworld.com/forums/a4-...s-yay-2376477/
You could try spark plug anti-foulers on top of the Wayne blocks to move the lambdas out further?