I don't take it in a bad way at all. I was told I should have a small maybe 1ft to 2ft rooster at cruise. I put diverter all way down on takeoff then tap up twice as I'm going. At a cruise I will tap diverter up acouple more times and feel boat get that light feeling but seems to start porpoising. The boat is new to me so I am learning came from 25 ft Deck boat with outdrive. I took a couple pics tonite of setup.
Not going to say it's wrong, but whoever told you the roost thing is clueless.
If your going to use that theory, the fastest boat I ever drove had at least a 7' rooster that was at least 200' long.
The hull simply has no idea how high the roost is.
Drive with your butt. Affectionately called the Ass-O-Nometer. Lol
Never mind what the tail is doing.
GT