Shafts aren't snapping. There's only been 2 failures and we only know for sure that just 1 of them was because the shaft snapped.. If it was a lubrication problem I would expect bearings failure first. If it was lots of shafts that would be different.On paper the TPC20 CHRA is realiable. But the fact is that shafts should not be snapping. Especially not at such low miles. I'm going to trust that the turbo was run at 28 psi and not overspun. I'm going to trust the DV was working to prevent surge (but @BecauseMotor has DSG). That leaves the most likely issue lubrication.