> “He leaped at the chance” and “He jumped at the opportunity” are very similar sentences expressing the same general sentiment, but they are not the same. The exact words we choose when writing matter. I want any LLM I use to choose the very best, most precise words at every single decision point.

Neither of these is "better" or "more precise"; in fact, LLMs will generally choose randomly between these candidates based on temperature, and SynthID should not distort the output of an LLM any more than the default temperature settings do already.

I agree that those are not the same sentences, but if the difference matters to you, you shouldn't be using an LLM. This difference exists at the level of what sounds better and is more evocative; to an LLM, nothing sounds like or evokes anything. They simply do not write good prose.