Docs: unclear behaviour of useRouter().prefetch() with static vs dynamic rendering

What is the improvement or update you wish to see?

Current document does not explain clearly how useRouter() prefetch behaves. For the prefetch with link, we have clarity on 3 possible scenarios / options:

null (default): Prefetch behavior depends on whether the route is static or dynamic. For static routes, the full route will be prefetched (including all its data). For dynamic routes, the partial route down to the nearest segment with a loading.js boundary will be prefetched.
true: The full route will be prefetched for both static and dynamic routes.
false: Prefetching will never happen both on entering the viewport and on hover.

It would be good to have the same explanation or, even better, flexibility, for the useRouter() prefetch. In addition, there is no clarity on how it handles parallel routing.

Is there any context that might help us understand?

E.g. if we want to prefetch the page following a form submission, and the subsequent page contains various dynamic elements, loading fallbacks and/or parallel routes, it is hard to achieve good instant page change without a clear understand of the useRouter().prefetch() behaviour.

Does the docs page already exist? Please link to it.

https://nextjs.org/docs/app/building-your-application/routing/linking-and-navigating#2-prefetching

Start with the linked Linking and Navigating documentation page and the useRouter().prefetch() entry point. Compare its behavior with the documented Link prefetch cases, including static and dynamic routes, loading boundaries, and parallel routes. Done means the page clearly describes these cases and explains how a form submission can prefetch the next page.