I make Muscadine all the time. Sometimes it can take up to three days before the yeast kicks in. But everybody else is correct in the fact that more yeast used isn't going to hurt anything. So you can give that a try. If you follow Jack Keller's recipe for Muscadine it's going to be almost impossible to mess up. The other thing I would suggest is not to let it go completely dry, about 5 to 6 days in the fermentation check the gravity again and do your calculations. If you're around 10 to 12% it is time to wean off The fermentation because if it goes to dry it's going to taste like rocket fuel. That is the problem with most fruit wines. If you nail the FG, it's going to taste amazing. The other problem with commercial md wine that I've tasted, is that they come out tasting like perfume smells. I have personally never had this problem, I don't understand why people like to make it like this. But if you keep it simple and back sweet and at the end slightly do your taste you're really going to enjoy this.