That sounds unnecessarily complex. Just force an authentication of the client (ergo, make it so you can’t access the API without logging in) and add api rate limits per user, maybe with higher limits on users that have the paid Reddit membership tier.

But I don’t think that was the point anyway. It’s less work to just start charging for the API. That way they can charge companies like OpenAI, and drive others to use their main app, letting them sell targeted adverts to them too.