One additional question - do you forsee any issues with this application where LLMs enter a non-value add "doom loop"? I can imagine a scenario where a test generation LLM gets hooked on the lower value simplistic tests, and yet management sees such a huge increase on the test metric ("100x increase in unit tests in an afternoon? Let's do it again!") that they continue to bloat the test suite to near-infinity. Now we're in a situation where all future training data is now training on complete cesspool of meaningless tests that technically add coverage, but mostly just to cover an edge case that only an LLM would create.
Not sure if that makes sense, but tl;dr - having LLMs in the loop for both code creation and code testing seems like it's a feedback loop waiting to happen, with what seems like solely negative repercussions for future LLM training data.