I agree with other posters that this is overly nitpicky. Take as an example playing a musical instrument. Perhaps you play cello in a community orchestra, and

I agree with other posters that this is overly nitpicky. Take as an example playing a musical instrument. Perhaps you play cello in a community orchestra, and you're presented with a piece that has a passage that you can't reliably or consistently play at performance tempo - maybe it has an awkward fingering or shift, or maybe requires a bow technique that you struggle with. But, maybe if you reduce the tempo to 80% of performance speed, you can hit it more-or-less consistently. The recommendation that is ingrained with all classical musicians in this scenario is to practice the challenging passage at this comfortable tempo with utter dedication to precision and execution. And when you can reliably and consistently execute at this tempo, notch up the speed a tiny bit - as little as 4 beats per minute. Repeat until you hit the consistency milestone, ad nauseam until you get to performance tempo (and then a bit on top for good measure). Per the article and per the top comment - there's a reason this is SOP for musicians. Deliberate practice right at the frontier of your capabilities expands that frontier, and lets you push further. By the way, "consistency" here might be, "play 100 times in a row without a single mistake." I've absolutely had lessons where we do this exercise with a gnarly passage, and when I make a mistake at repetition 79, we start the counter back at 0. It's tedious, laborious, and exhausting - but it works.