CURL has been scanned with multiple LLMs. Mythos was last and as a result found only 1 issue. If Myhos was really much better I'd expect it to find a lot more issues despite the others already there.

Also, the competing models are getting better. Opus 4.5 was better than everyone else when it was new, but only a few months later and there are a lot of models that are better (not just the newer Opus models)