@JLNobody,
I think I understand what you are saying.
I do have a meditative practice, and a physical practice, not specifically in the zen tradition but in yoga (specifically tantra/vajrayana). I don't so much view my meditative practice as negating dualism, but rather transcending it. Dualism being an upaya toward trans-dualistic understanding.
When you speak of language, I think you mean something like human language or internal dialogue. I meant language in an even broader sense of distinction, and include with it all of the interactions which led to our physical presence in reality (evolution of life, societies, etc). I don't think that cerebral activity is possible without distinction. This is the condition that must be overcome in order to understand something beyond distinction.
I wonder if you are including thinking that does not exclude the middle as still being a form of dualism. There are dualistic ways of reaching that understanding (non-excluded middle). I think that in zen this is often demonstrated with paradox.
The problem I often see in zen is a difficulty in distinguishing "
the lifting of the curtain" from negation of reality (nihilism, etc.) I think that having an ethical practice helps make that view (nihilism) less easy to slip into.