I agree with the sentiment, but asking someone to effectively screen record their work is a huge ask in terms of privacy invasion, not to mention a huge admin burden in terms of reviewing it.

It might be simpler to ask them specific questions about the code base itself and why they did particular things. You might be able to recognise llms tics easier - assuming they copy and paste the responses.

I don't think most people would just copy-paste the responses, since it's very obvious when you do that. But the idea is definitely good. I also think some people who AI-generate FOSS contributions genuinely like the idea of FOSS and want to support it, but don't know how to code. Although tbf they could just donate.