The problem with that is that some kind fellow on GitHub will clone the project, uncomment the code to enable the premium features for free, and change its name. If it's released under a FOSS license, the original authors have little recourse.
This is what happened with Emby (a media server like Plex). The backend was open source and there was a license to activate premium features. Somebody cloned it, and then released the premium features to everyone for free.
This is what happened with Emby (a media server like Plex). The backend was open source and there was a license to activate premium features. Somebody cloned it, and then released the premium features to everyone for free.