> the most impactful changes

Quite a lot of our bugs in production have been in seemingly less impactful changes. How do you know what's impactful a priori?

> I can have an agent mass-produce security bug fixes

I can't figure out what you're trying to say here. Are you saying that this is acceptable? Because I very much don't think it is. You'll have twice the bugs after you're done, and they'll be inhuman ones that you have little chance of catching.

> But how many changes are actually serious?

I mean, "security bug fixes" are not on your list of serious changes? What is?