I've thought long and hard about using a flourocarbon leader or even main line for trout baits. The conclusion I came to was that it was not a good idea. So many trout bait fish hit the bait right at the boat, and with flourocarbon you don't have the stretch and shock absorbsion that you do with mono. In this instance, you want a little stretch in the line so that the fish doesn't clean snap you off. A big fish that eats the bait right at the boat is challenging enough, the bait, rod, and line all have to give in order to ensure a hookset.
Just my 2 cents. CJ.