Honestly, if I were in your situation, finances having changed drastically to where maintaining the Audi is unaffordable, I’d consider selling it with full disclosure and looking at the possibility of trading the Focus foo one that’s easier for you to drive. Audis are nice cars, but they do cost more to support than most. Meanwhile, you could raise the air pressur ein your tires a bit above the recommended amount (perhaps 5 psi) to help eas the steering pain a bit. I have a friend who does this. She realizes she has to sacrifice tire wear, but it’s a small price to pay to prevent pain.
Unfortunately, once the warranty expires we all end up having to pay for correcting any design mistakes that then present themselves. You could write to Audi, but don’t get too optimistic.
Nice work on your research, by the way.