The way I understand the gunicord documentation, this has the same effect as if you set up a script which listens for file changes and restarts the server (or workers) every time a file changes.
That's way less efficient compare to how PHP handles it.
I don't want processes to be killed and new ones to be started every time I change a file.
PHP does it the right way: Only when a request that touches outdated code hits the server is that outdated code reparsed. As long as you just edit files, it uses up no resources at all.