Bought into one of those myself a couple years back, a $27 thing about spotting lies through eye movement, and I gotta say you're being a little harsh on the whole idea. Yeah, a lot of these gurus are just selling snake oil and recycling the same tired nose-touch stuff, and that guy sounds like a total hack who never showed you a single real study. But body language itself is not fake, there is actual research behind things like baseline behavior and clusters of cues, it's just that real training takes months and these cheap courses cut every corner to fit 6 hours. The problem is not the topic, it's the $15 price tag promising a magic skill that doesn't exist at that price or speed. Eat the cost and move on, but don't write off the whole field just because one TikTok clown ripped you off.

Did you track the chip color when you dropped the speed? I ran the same deal on 4140 for years and always went hot and fast because that is what the old timers drilled into me. Then I tried backing off the sfm and my tool life went way up, just like yours. Turns out I was cooking the edge and calling it productive. Took me a decade to admit the slow way was the cheap way.