Huge respect to the author for ealizing this - however, I'm honestly sceptical of including yet another turing-complete configuration DSL without sufficient debugging capabilities.

Seems to me, now you've added several more sources of complexity:

- You have to get the JSONnet syntax right and learn about th various functionalities and expressions.

- You have to ensure Jsonnet is correctly translated into the GMail filter chain.

- You still have to ensure the GMail filter chain works correctly - this is one of the original problems this project set out to solve, but I don't understand what additional tools the project gives you to archieve this.