Sorry but we were not talking about “rsyncing the files over”. We are talking about what services that i've used like Forge or Ploi do where you deploy project into separate folder and then switch symlink. You can even roll it back.

I have a feeling you want to dunk on poor dumb PHP developer but like Forge is by the people who created Laravel. I believe they would put some thought into it. Maybe just maybe small chance of one bad request is not such a bad deal.