GPT4o and 4.1 are definitely not the best models to use here. Use Claude 3.5/3.7, Gemini Pro 2.5 or o3. All of them work really well for small files.
What are people using to interface with Gemini Pro 2.5? I'm using Claude Code with Claude Sonnet 3.7, and Codex with OpenAI, but Codex with Gemini didn't seem to work very well last week, kept telling me to go make this or that change in the code rather than doing it itself.