I use ...\pserve development.ini --reload in my dev environment to restart my API when code change.
The doc says:

Auto-template-reload behavior is not recommended for production sites
  as it slows rendering slightly; it’s usually only desirable during
  development.

But the doc has no proposition for a production environment. What's the recommendation to reload, do I have to make it manually every time?
Yes, you will need to restart the service if you change anything in your config file.
If you know that you'll be changing things and don't want to restart it every time that happens, move some of your configs to a database and refactor your app to read from that. This won't be possible for everything, and you'll need to be careful that when an update happens it is applied correctly, but it can be done for some things.
Deploy/Reload code from python pyramid project in production