Yeah, China is interesting with this stuff. I know there is an idea that it's the wild west over there--and to a certain extent it is. Plus, you do have the issue that guys like me (who are normally living there part of the year) are forced to work remotely, so QC is more tricky. Add in raw material shortages and extreme levels of demand, and no question there are going to be higher failure rates on some parts. The flip side is that the inspection process is still relatively robust. It's not immune to red envelopes in exchange for a sideways look, but the country runs less on bribes than it used to... And yes, the insurance companies help keep it honest. Every supplier has to be bonded and the companies that issue the bonds do their own audits.
Talking about stems specifically though, ironically I think low-end forged AL is probably the strongest out there. They'll typically err on the side of "heavier", and in my experience forging is a more robust way to make a stem. Tig welded chromoly is great is you have really tight controls (think old Salsa stems made in Petaluma), but there are way more things to go wrong with big productions (hence the Salsa recall when they started mass producing these at QPB). Most of the stem recalls involve welded stems (or stems without enough material).
There's more prep involved, and more humans involved--and that increases the margin for error.
