Yes, I used it last year in my hard ciders. I don't know if it made any difference, or not. I should have done a split batch, half with the MLF enzymes, and half without. I probably won't use it in the future. But, if I do, I would split a batch just to see what, if any, difference there might be.
Primaries - Empty
Secondary - Several Hard Ciders, Traditional Bock
Kegged - Czech Pilsner
Bulk Aging - Brewtopia Barleywine