TL;DR will be at the bottom. However, there is a substantive amount of historical context to this post that needs to be explained for this to make sense.

Chapter the First: James the First

King Jame Charles the 1st was executed in 1649 under the authority (dubiously) of the High Court of Justice; however, as this was allowed to happen, it set a few precedents. Firstly, The Monarch must follow the law. Secondly, the court justified the charges of treason against "The Crown" as sovereignty coming from the people, stating that the people were sovereign as they voted for Parliament and then gave power to the King. This established the precedent of Popular sovereignty, which noted that the ultimate power resided with the people, represented by parliament, and not the monarch.

This led to a period of turbulence, and eventually, Charles the Second was deposed and replaced by Geroge the 1st (massively oversimplified.) In combination with the Bill of Rights 1689, The Act of Settlement 1701 and The Acts of Union 1707 (which also made the Union Jack what it is today.) These three laws led to Parliament's firm sovereignty and what the "Westminster" system is today (again, oversimplification.)

Chapter Two: Colonial New Zealand

New Zealand's sovereignty is much more recent. New Zealand started as a colony with the New Zealand Consitution Act of 1852, creating New Zealand's first Government, an amendment in 1857 to allow the colony to change its constitution (rather than need the UK). We are no longer subservient to the United Kingdom and ended being a Dominion in 1947 when we adopted the Statute of Westminster 1931 into our law.

Our Parliament is affirmed sovereign due to the New Zealand Consitution Act 1986, which replaced the 1857 Act. Now, we can apply that we are an independent Nation and return to the context of the first Chapter. That we, the people, are sovereign as granted by the vote. We have to elect a parliament. What Seymour proposes is already given to all of us (unless you're in prison, are not a permanent resident, or are not a citizen). We, New Zealanders already have Soverignty, (whatever Seymour thinks 'tino rangatiratanga' is), what we don't have is Tino Rangitiratanga for Tangata Whenua.

Chapter Toru: Māori Sovereignty, Tino Rangatiratanga

Firstly Seymour's assumption that "New Zealanders" (translated back to English from Te Tiriti) meant non-Māori is mistaken, as the only New Zealanders that existed were Māori. However, this continues on the assumption that he is correct; it is just a rub-in of how incorrect he is, that even if we follow his proposed model, we can end up with a conclusion he would despise.

For those who don't know, Tanagata Tiriti are those who have entered New Zealand after 1840 or identify as their descendants. Tangata Whenua are those whose ancestors have been here since before, specifically those apart of Iwi who signed Te Tiriti, which is the correct definition.

So now that we know what Seymour wants (Tino Rangitiratanga for all, which the best translation we have is Soverignty), we already have for Tanagata Tiriti; what do Māori want?

Tanagata Tiriti already has the sovereignty promised to all under Seymour's interpretation. However, Seymour's definition isn't mutually exclusive with a Māori Parliament in the historical English interpretation of Popular Sovereignty. What our current setup does allow for, however, is the return of a Second House. A Māori house? Maybe. We used to have an equivalent to a House of Lords called the Legislative Council, which was elected and voted to dissolve itself in 1951. The Legislative Council Chambers still exist. This Council would fill the role of what the Governor General does, checking legislation for quality before signing it into law (again, oversimplified) and potentially having the ability to propose its own for the House of Representatives (hint: Representatives) to vote on.

The proposal of a Māori house would make sense, by Seymour's own definition, with acceptance of Popular sovereignty being his goal. This would also not be mutually exclusive with equality; it maintains one vote, and both houses hold the same power(s), which would be the "Higher" chamber, which is mainly ceremonial.

That being said, I am Tangata Tiriti, and the model Māori may want could be entirely different, as this still is within a Colonial system.

Too Long, Didn't Read

(I'm sorry; I really tried to condense it)

Chapter the First: James the First

• James I was executed in 1649, setting the precedent that the monarch must follow the law.
• Sovereignty was established as coming from the people, not the monarch, leading to popular sovereignty.
• This led to the deposition of Charles II and the establishment of parliamentary sovereignty with the Bill of Rights 1689, Act of Settlement 1701, and Acts of Union 1707.

Chapter Two: Colonial New Zealand

• New Zealand's sovereignty evolved from the New Zealand Constitution Act 1852.
• Full sovereignty was affirmed with the Statute of Westminster Adoption Act 1947 and the New Zealand Constitution Act 1986.
• Therefore, New Zealanders Tangata Tiriti and Tangata Whenua are already sovereign.

Chapter Toru: Māori Sovereignty, Tino Rangatiratanga

• Seymour's interpretation of "New Zealanders" as non-Māori is incorrect; initially, only Māori were the only New Zealanders at the time of signing.
• Tangata Tiriti (those entering NZ after 1840) and Tangata Whenua (Indigenous Māori) have different sovereignties; this differing sovereignty does not reduce the inherent sovereignty of the other group when applied to its full extent, as both groups are already sovereign.

If you read nothing else:

A Māori House could be a modern interpretation of historical popular sovereignty and would fit within Seymour's own definitions. However, with what Seymour wants to re-write, it would no longer be allowed, as Seymour wants to redefine who is Tangata Tiriti and who is Tanagata Wehnua, not who is sovereign and who is not.

I am open to questions. I will reply once, but if I feel you're being intentionally inflammatory, I will nap if I think you're being deliberately inflammatory.