I do love the Ian Knot, and I taught myself to do it for a while. Alas I stopped wearing lace-up shoes for some years and when I went back to them the muscle-memory for the standard knot was strong, so I just stuck with it.

There's an 80s era tip of my tongue movie with glob of dialogue abut the inventor of the aglet living the American dream becoming insanely rich from Nth of a cent per shoelace royalties.

Yeah, there's actually been a lot of research on that. 100ms is generally considered to be the threshold between perceiving a delay or not. But even that needs some additional context. That's the threshold for feeling like you're waiting to get a response after completing an input. But a 100ms round-trip delay on a mouse cursor would feel like you were using a broken computer. And when you're doing something where you're used to continuous feedback from your input, you can sense incredibly small changes in the response time. +/- 10ms from what you're familiar with is noticeable for almost everyone. There are people who consistently notice half of that - but remember that's in the context of difference in latency of continuous feedback. 100ms is a pretty good rule of thumb for the threshold of "why am I waiting for this?"