Wouldn't that make it a better to distinguish whether Mythos is uniquely super powerful vs an incremental improvement from Opus etc that are routinely used as the basis for bug reports/fixes in cURL?

If Mythos found a hundred new show stopper bugs then it would have meant Opus missed them and therefore closer to a "step change". Otherwise it implies the difference in capability isn't nearly that stark. Mythos finding 100 low-hanging bugs in a less scrutinized/hardened project on the wouldn't be as useful signal to answer that.