Known unknown: Section 13, Where this breaks, and what is unknown: "I found no time series of coefficient drift…"

[anacay]

I found no time series of coefficient drift

How often does a coefficient move, and by how much, across a hardware generation or a code change? I haven't found a public series. Even the shape of one would help: a ratio over two or three years, numbers disguised or indexed. Is drift a slow creep, or mostly a few big steps?

Author's note 1 on Section 13, Where this breaks, and what is unknown. Reply below; if this settles into a change to the text, an editor will carry it over with credit (see HOW_IT_GROWS.md).