I'm not sure it needs to be mentioned in the change proposal - but there are some caveats to this as it applies to the workstation:
* There are no plans to add any user interface to enable/disable modules in the GNOME Software user interface.
* If we even want graphical applications from enabled modules to appear in GNOME Software, someone is going to have to put work into appstream enabling modules, and into filtering the appstream data based on enabled modules.
* For Fedora Silverblue, if we want users to be able to layer rpms from modules, then rpm-ostree will likely need work.
For the Workstation in general we want to move to a model where the system install set is stable and enables basic functionality, and containers are where you do sysadmin experimentation and development. Silverblue is the long-term version of this, but we encourage this way of working even for RPM-based installations.
So ideally documentation about trying out modularity on Fedora Workstation for something like a different version of nodejs would show doing that inside a container. (With the caveat that we're still figuring out what the recommended best practices are for pet containers.)