Hmmm... Just thought I'd post an update here.
While fitting the new Unicomp keycaps to my customised Model M I noticed some of the stems are indeed "twisted". Out of the 63 I put on the board, 7 were cockeyed and had to be switched. Also, a number of the top parts of the keycaps had miscolouration or a small dye spot. And what's with the random stem colours?
Anyhow, I'm happy enough putting Unicomp parts on my old Model M (after all it's not exactly a precision machine, rather rattly and wobbly compared to my MX boards), they're relatively affordable, but their quality control is definitely NOT up to modern European standards. I'm more picky about what goes onto my customised MX board, though.
Anyhow, it seems in some companies that complacency and lack of innovation / continuing research and improvement has led to quality control being somewhat lacking when compared to equivalent European and Japanese products. Unicomp appears to be one of these. Some of the American car companies have had the same issue and it's led to rather a problem in "Motor City". At least the latest Corvette is one model that's headed back in the right direction. It's not an "American only" thing, though. I'd say Cherry have run foul of the same issue. Although the quality is still better than Unicomp, the latest batches of switches do have more issues than in the past ("scratchy" lower casings / sliders, some upper casings with "flashing" from molds interfering with keycap stems, etc. And no new product offerings despite long term feedback about things that could be improved, like a larger tactile bump on Browns for instance). The only "new" product is the clear "RGB" casing design and it's not much of an innovation, really, considering Matias introduced it years ago.