@peeja: I'd love to help finding that transducer. I've been working on a refactoring that might be of help. The main idea is to make it easier to see the quick-check loop as a state machine. I think we could be closer to extract a transducer from there. The changes are in the test.check.refactor branch in my fork, let me know if you have any questions or comments

-- that's related to your message from a few days ago 🙂