> Eg: is there a clean way to dual license such that hobbyist, and exploratory work (eg: a proof of concept done in a commercial setting) are allowed, but using it in production requires a fee?

Yes, it's called language. Contracts are nothing but text, so why don't you just write down what you think should be the rules around using your software by other people?

I get the urge of a lot of developers to pick an existing third party license from the shelf, but just as you can write your own code - and are not required to use ready-made libraries/frameworks - you can write your own open source license for your software.