I own one of the very first Tecsun BCL-2000s (the original Chinese version
of the S350) to be shipped outside of China, and I have never seen a reason
to "fix" this radio.

Sure, the frequency drifts some. I consider it a badge of honor to own an
analog radio with a little drift. But this radio's real charm is its size,
its look (I have one of the original candy-apple red ones), its sound, and
its sensitivity. I am 100% satisfied with mine, and wouldn't pay a penny
more for any of the latest version's supposed improvements.