I did a similar project that I pitched to a few VCs, got negative feedback, then saw Vercel (was Zeit at the time) launch that feature. So I archived the project & OS'd it. Guess I should have pressed on
I think this might also have to do with timing. As in, this "per-PR" iteration model is now becoming popular. In our minds, after CI/CD, the next thing to automate are ~full deployments.
Runnable did this and got acquired by MuleSoft. Heroku also has this feature. Vercel is less comparable since it's only for serverless. Can you link to your project?