This is about "available source, but licensed such that some included use cases must pay while others don't".
I'm not sure it works. Originally tried by Sleepycat 25 years ago. Problem is that your project/product becomes incompatible with all other OSS. So everyone else will go out of their way to avoid using your thing.
Delayed Open Source publication (DOSP) is a concept established by the Open Source Initiative (OSI). It is in keeping with OSI's public-benefit mandate to "persuade organizations and software authors to distribute source software freely they otherwise would not distribute." DOSP ensures that if a Fair Source company goes out of business, or develops its products in an undesired direction, the community or another company can pick up and move forward. Will this be meaningful in practice? Again, time will tell.