Hi Van, excellent thread. Thanks to all the contributors.
Please thank Seizan , I identify with his take , I also found his reasoning behind the other kata and their attributes a logical one , and the best reason for the extra forms I have heard yet , always informative.
Ray's opinion is probably shared by many and not invalid, I personally find the nature of the form brings you too obey the alignments and physics.
Words are often inadequate, I don't recommend ignoring the form, just that departures from it and errors are often more to do with missing balance harmonious motion than errors in technical mimicry.
Of course good instruction, understanding and patience are always helpful, but I find approached correctly the nature of the Kata to point you towards your most efficient, and therefore the most natural you.
Deviations must fit Sanchin if your honest to the work, they change or are dismissed, and each step brings you further.
While there is an undeniable alignment and physical element, its a complicated matter, its definitely the place to start, but so much more complex than a simple model can give us, Sanchin to me lets us learn about ourselves beyond our preconceptions, there is art in movement, everyone is different and so should their sanchin, the mechanics and levers, the muscular development, the postural chains and tension chains, all differ, yes there is science
Most never reach the stage where they realize their body feel, their mindset and their postural habits can even be different than they are.
How we feel about our practice can have a huge impact on our physicality, how we think, our feeling state, our body being.
Because of the balance and nature of the form there's real feedback, an opportunity to find a datum of self.
Of course this is really a personal journey, and perspectives and opinions will vary.
Words don't do any of it justice , but I am glad I wrote the piece , as I have learnt from the contributions.
I have done over forty forms, but none but Sanchin has captured this feedback for me.