Some do this by using tools like RepoPrompt to read entire files into GPT-5 Pro, and then using GPT-5 Pro to send the relevant context and work plan to Codex so that it can skip needing to poke around files. If you give it the context, it won't spend that time looking for it. But then you spend time with Pro (which can ingest entire files at once instead of searching through them, and provide a better plan for Codex, though)