It really depends on your fruit load. Low fruit loads; 1-3 lbs/gallon, I'd mostly ignore it, perhaps offset 50ppm YAN. Higher than that, you may want to offset up to 150ppm YAN.I am about to start my first batch of mead, so this thread has been helpful reading. I found a good calculator to determine the amount of nutrients to add according to a nutrient schedule.
Once I make a basic mead, I want to try a melomel. The fruit will probably contribute some YAN and other nutrients, but I don't have a way to measure that. For those who make melomels, do you just ignore the presence of the fruit and calculate the nutrient amounts as though the fruit was not present?