i use codex to do initial research and draft texts (in typst). i use files-output skill so that all research contexts are rendered into files md files.
i do second phase on codex, by asking to download all pdfs and extract all text of laws it references. can repeat fully local research step.
after i ask gemini to find issues and criticize.
UPDATE: there many legal skills on github to try, not used so any yet
Are you a lawyer yourself?