I do not question the subsidary benefits in the least of alternate surface areas, nor drills designed to isolate or enhanse perception, awareness/usage of assorted bodily connections by such subsidary methods.
My bias exists with this explaination (or more correctly this type of explaination) being the primary-fundamental function of the mechanics of the form.
It smacks of ~myth~ this type of explaination (ie back to a wall, on a boat, etc., etc.) of a scale I have difficulty verbalizing... Yet despite my valueless skepticism, it still persists. It (board balancing) is hard to swallow as the primary/fundamental reason by which to use these mechanics, principles, movements...
<<if anyone talks about them...
True... and though certainly not X's original proposal to explain the ideas, whispers of this kata... I would love to hear/know of others who practice the more troublesome (ie respectfully "seemingly absurd") explainations of this form. Better yet, any who are told it (Neihanchi kata) is specifically for usage on a boat, in the rice paddies, back to the wall, so forth.
I will be amazed if the practice was ever spoken of in those "locals"... further back than the American WW2 soldier.
<<And we haven't gotten into my naifanchi training practices with turns in the kata (from a friend in Shimabuku Ezio lineage Shorin)
More please...... turns, the full blown 180 degree variety? Now that I'd love to see...
<<or my teenager niafanchi he**, naifanchi done with jumping turning crescent kicks.
Aside from tiring them out, how did you draw crescent... no I'm sorry JUMPING & TURNING crescent kicks from the Okinawan Neihanchi form
Best wishes training...
And you as well my friend