I used ML fermentation on both a Chard and a Cab from WineXperts. I got some pretty good results. I'm still working on how to do a better MLF on a Chard.
I did the MLF after the primary fermentation was done, and before I racked off on the Chard, and before bulk aging.
It also worked on the Cab, as well. The cab had a more rounded mouthfeel and lost some of that "sharpness" you get with some kit reds.
I used the base model Vintners reserve Chard kit and the World Vinyard French Cab kit for the red. I used the lower end kits so if they were totally screwed up and undrinkable in the end, I wouldn't be out much.
Any time I read Winemaker and I see something the pros do that I am not doing or haven't tried, I usually run right out and try it! What the hell, right?
Edison didn't fail 5000 times inventing the lightbulb, he found 4999 other ways NOT to make a lightbulb. I say try it, and see what you get.