As many of you, I have multiple subscriptions to Claude and Codex. It's a daily occurrence for me to use 2-3 accounts for the same conversation. The point for me is to switch the account where the usage is taken from, not the configuration.
I made something simple & transparent named Switcheroo: https://github.com/FTCHD/switcheroo
Works with other AI CLIs like Gemini, and other various CLIs like Vercel (if you're managing multiple accounts like me), Netlify, Github etc