Is it really necessary to suggest that if you say Nam that is the same as contracting the Nembutsu? I don't know the full implications of what you mean by that comparison, but its dismissive in the least.
I was not trying to convince you or anyone that Nam is preferable to Namu. Nam is what I say and I explained why it appeals to me. I did not mention this in this thread - I have tried Namu, but the extra syllable did not sit well with me; that was where I was coming from. I do not intend that my reasons for preferring one pronunciation over the other should be compelling to others. I shared that detail in the spirit of discussion; it may not find resonance with some, but it may find resonance with others. If you don't find my reason compelling, well... Tatha - it is what it is.
In considering this subject, I have not found any compelling basis for insisting that the Daimoku should be said one way or another - some of which I mentioned before in my observation of practice at various temples in Japan.
I have been told that Nam is what Nichiren Shonin said. I have also heard people insist that Namu is correct. Whether one says "Nam" or "Namu", it usually comes back to, "This is what I was taught." Do any of us alive know what Nichiren actually chanted? No, all we have is hearsay. We do the best with the resources we have to determine the the proper practice for ourselves, and this ultimately includes our own preferences and capabilities. Even if we did know what the Founder said, would it really make a difference about people's preferences? Are we really going to insist that ♫♩♩♩♩♩ is the proper rhythmic phrase for the recitation of the Daimoku over ♩♩♩♩♩♩ just because our teachers tell us its right? What basis do they have for that other than the tradition they received? Did any of these teachers speak with Nichiren, let alone Shakyamuni, and receive instruction that one pronunciation is correct and all others are wrong and ineffective? Nichiren Shonin stated that his Daimoku was the same as the 24 character Daimoku of Fukyo Bosatsu; this suggests that the particular pronunciation of the Buddha's teaching is nothing more than a matter of convention.
Not to beat this subject further, if we carry this concern about proper pronunciation to its conclusion, everyone who can't pronounce the Daimoku with medieval Japanese pronunciation is doing it wrong. That is ridiculous. The last thing we need in the Nichiren community is yet another criteria to run an orthodoxy prosecution.
Some people say toe-may-toe, others say toe-mah-toe. A ripe garden grown, vine ripened tomato tastes great no matter what you call it. People who want schism, will find reason for schism. I want reconciliation and fellowship. Some matters are worth the energy of debate. Conventions of verbal expressions of teachings and what we do as our personal practice does not seem to be one of them. At least to me.