Your 50k+ mile experience is exceptional to some performance car owners who replace clutches at 20-25k miles, and a shock to others who experience 100k miles. I read of many N54 owners anxious to wear out their twins so they can update with larger twins or the latest big single turbo kits. I also know you are in the first wave of e89 owners out of warranty as no one is older than 4 years, if I do the math correct. The opportunity to apply increased boost to a fresh set of turbo and dual clutches is enviable. It's a perspective thing, like lemons and lemonade. Good luck with your return to flight and send pics of the mechanical findings during the rebuild/replace process.