I work at Auth0 and we are building a Zanzibar inspired SaaS as well (you can read here if interested https://twitter.com/auth0lab) and it is positive to see that there's interest in services like this, it's validating :)

One of the things we found is that learning Zanzibar concepts can be a bit daunting, so we put together this playground: https://sandman-86.herokuapp.com/, that has samples and tutorials, etc.

Hopefully that's useful for others getting started with Zanzibar. We are likely going to be adding the ability to write to the playground (it is read-only today) in the next few months.