> Since then OpenAI has refreshed the weights behind the “gpt-4.1” alias a couple of times, and one of those updates fixed the em-dash miss.
I don't know where you are getting this information from... The only snapshot of gpt-4.1 is gpt-4.1-2025-04-14 (mid-April), and the gpt-4.1 alias still points to it [1].
Just to be sure, I re-ran my test specifying that particular snapshot and am still getting a 100% pass rate.