Mangrove Jack's Empire is another of those low attenuators. I think it's a version of the Newcastle yeast. I think I got in the 60%s last time I used it. As long as it tastes good it doesn't matter what the hydrometer says.
Almost every Mangrove Jack's yeast I've ever used has been a low attenuator. That's why I tend not to use them anymore.
That's not a fair assessment. MJ just repacks yeast from others, so this is just like saying "I don't like Lallemand because I tried Windsor once." Uh, yeah, well, you used Windsor, so...
Indeed, Empire is probably just Windsor.
But if you try any of the diastaticus repacks, you won't be complaining about low attenuation, I can guarantee that.