The "paper" you might be looking for is likely one of the many security research reports technical blogs
Users should be aware that deploying reverse proxies or unblockers on Vercel carries significant risks. Vercel actively monitors for proxy services, and accounts hosting such tools may be suspended or banned for violating Terms of Service. The vercel-reverse-proxy documentation explicitly warns that "if you directly fork it might be banned" and advises creating a new repository and copying the code over instead. vercel.app unblocker
This is how they generally work: