You can see the influence in all taekwondo forms from ITF and WTF , any form that follows the " I " pattern of movement, palgwe and taegeuk series of poomse all follow it. Directly taken from the shotokan Heian series of kata, which are from the okinawan Pinan series which were constructed by itosu and possibly matsumura. The differences between heian and pinan are slight and can easily be seen by comparing the shotokan katas with the matsubayashi-ryu, these are supposibly exactly the way nagamine was taught... as he wanted to preserve the way it was originally done. This is all speculation though, as you never know what is true and what isnt, even if it is from a reliable source.
Mastery is in the practice itself.