Secrets that I know...I only use it as my top thread and use a finer thread...such as Aurafil in the bobbin. I do have a friend who has used it both top and bottom and and said she was told to only fill bobbin about 3/4 full and wind it slowly.
I don't sew too fast with the invisible thread...use YLI brand, but am wanting to try the newer invisible polyester thread now available. For me, it works best to have the thread upright, not horizontal when feeding onto the machine. You will need to decrease the top thread when sewing with the invisible thread. Start by lowering it a bit, and sewing a sample, then another bit until the tension is what you are wanting-no bobbin thread showing on the top of quilt.