It's (of course) not the ball joints!
According to my opinion, the competent mechanic determined, after some moderate disassembly and unsuccessful adjustments of the steering linkage, that there is play in the steering column itself within the steering linkage; that is, when the tie rod end is disconnected, the steering column can be moved back and forth.
Conclusion:
A stunned KD champion: 'Something like this has never happened before!'
and a new steering rack at the company's expense (VAG).
Once it's installed, I'll let you know.