How can adding a tiny amount of the right material push a whole batch of chocolate toward a tempered-like structure?

Answer: It seeds Form V growth

It dilutes the cocoa butter — This is the dilution misconception. A tiny addition is too small to work mainly by replacing cocoa butter. The cited result is structural: a small fraction can stabilize Form V and induce commercial-tempered-like chocolate, so the effect is more like steering growth than watering it down.

It prevents crystal growth — This is a plausible overcorrection: if bad crystals are the problem, stopping crystals may sound helpful. But chocolate needs a crystal network; the trick is biasing it toward the desired form. The useful contrast is that good tempering controls growth rather than preventing it.

It seeds Form V growth ✓ — Correct. Nature Communications reports that 0.1% phospholipids can stabilize Form V and induce commercial-tempered-like chocolate. That is a seeding idea: a small stable cue biases how the larger fat network grows. The surprise is how little material can redirect a bulk texture.