How to maintain a private Guix fork

The usual way for customizing Guix is creating a custom channel.

I choose to fork Guix default channel, in a private branch for these reasons:

• it is easier to customize system level settings like mounting of bcachefs and symilar things, and use them directly in my working environment (i.e. “eating your own dog food”);
• I can send patches directly to Guix upstream, while in a channel I need to transform them;

I installed Guix from source code, as described here.