I have some medium difficulty math problems where I have used the models for the last year and a half repeatedly. Back then they were already good at pointing out obstructions and constructing counterexamples. So that tracks. But at first glance it looks like Fable actually made real progress on one problem for the first time.

A year ago my judgement was that I had wasted my time on trying to work with the models and doing things myself would have been more productive as I would have gained intuition from the failures. Now it definitely seems to have figured out stuff that would have taken me more time than I have to spare on this problem...