The research I've seen most recently indicates that oxygen access is a driver of STA1 gene expression, dependent upon another gene, but it's been a while since I looked. My hypothesis is that this is why open fermentation with the Dupont strain anecdotally helps avoid the "stall" (as opposed to the invalid but oft cited "pressure sensitivity" theory). That said higher temps seem to push it along faster (which has been my experience with Dupont- insanely high temp, no stall).
I intend, at some point, to experiment with a secondary blast of oxygen with the Dupont yeast to see how it behaves with or without insanely high temps, though I haven't done a pure culture fermentation with it in years (blended strains containing it are easier to work with).
I've only used one STA1+ yeast that didn't attenuate well into the 90% realm. Every other one has very highly attenuated, though not at the same rate. I accept that "many" don't as that seems a pretty consistent consensus (even apart from yeast companies with a financial stake), but I haven't come close to using every option out there and never will. Given my experience, with any STA1+ yeast I do not take for granted that a couple days stable gravity means it's done unless coupled with very high attenuation as well (the French strain for example will do it's work very quickly).