Can anyone point me to any zk-based application’s codebase that features fuzz-tests for its core smart contract?

I’m working on a zk-based privacy application and we’ve started on the process of fuzz-testing our core (zk-snark based) smart contracts.
We started our approach with Echidna (utilizing etheno for E2E testing). That decision was made based on the fact that our codebase utilizes the Hardhat framework, but it looks there are many issues with echidna and crytic-compile and the experience has not been as smooth.
The main issue with fuzzing zk-based SCs are that the proofs are generated outside in a more complex process than usual through the circuits, and having not developed over foundry yet, I’m worried if we can migrate our crypto-based scripts (currently in TS) to foundry, which utilizes solidity scripting..

Also, there doesn’t seem to be any zk-based protocol that has hosted its fuzz-tests in github with echidna. So, it’d be really helpful to get pointers to any public zkp-based codebase that has fuzz-tests for its core SCs for reference..

Lastly, recommendations on which framework: (Echidna + hardhat) or Foundry (standalone or with HH) would be best for going forward with fuzz-testing the zk-based SCs would be highly appreciated.