Yes and no. The applications for Tachimura no Naihanchi work because of the mechanics used in that kata, and those mechanics are generally not used in Itosu's kata. You can still use those applications, or take inspiration from them, but they won't totally fit the way the kata are practiced. There are, of course, a few that will work even if you change the mechanics, and those are the easiest to make a connection between the two styles. They are really made from Passai, Kusanku, and Chinto, more than Naihanchi, although Naihanchi does tie into Passai and Kusanku, historically. I'm sure that he considered applications when building the Pinan kata, but he was also using his Naha-Te (learned from Nagahama) to reshape the kata that he learned from Matsumura. I believe that is why there is such a significant difference between how Itosu's kata are performed and how KishimotoDi, or even Matsumura Seito or Ryukyu Kenpo are performed. The sweep in Gekisai is definitely similar to the scissor throws in Tachimura no Naihanchi, but is very upright, without any sinkin/rising action, and usually without much twisting. A more similar technique is actually the gedan-barai in Pinan Godan, just before the hammerfist/elbow sequence. You can ALWAYS use the applications from any style in your practice, and use it to help inform your training. Even if they don't exactly match up, they can provide inspiration or be useful tools, on their own. Thanks for answering my question