I wish they would cryptographically sign the repository, so potential Lean "exploits" can be discovered in due time.
The Lean system has already experienced soundness bugs.
The question is, will future generations doublecheck this proof with a frozen Lean system of today? There is a lot of incentive in having LLM's be the first to find high profile theorems like this.
I wouldn't vouch my hand in fire in asserting the validity of this gigantic proof.