Go slow to go fast. Breaking up the PR this way also allows later humans and AI alike to understand the codebase. Slowing down the PR process with standards lets the project move faster overall.

If there is some bug that slips by review, having the PR broken down semantically allows quicker analysis and recovery later for one case. Even if you have AI reviewing new Node.js releases for if you want to take in the new version - the commit log will be more analyzable by the AI with semantic commits.

Treating the code as throwaway is valid in a few small contexts, but that is not the case for PRs going into maintained projects like Node.js.