if its the loose feeling you want, thats all in the tail and fins, and if the board floats you well enough, itll pivot wherever you want it to if its set up as a quad or a twinny. the middle fin is what gives you stability in a juicy wave, but you dont need one for anything under head high. then again, if youre good enough you can ride any setup in any wave type, but im speaking for most people, not some world class surfer.
but back to the question at hand, twinnys like these are gonna be fun in mushy waves under a few feet overhead, but once it gets about that big i hope you have something for a better wave so you dont have to turtle the board through whitewash. a full nose will get you some paddle power, and a full tail will get you into the wave.
i worked at a shop for years and have repped a few surf companies, i love answering questions about surfing even though yours wasnt directed at me haha. hope this helps.
