Its really not that impossible to tell. There's loads of work done over years by historians and lawyers that have helped to bring understanding to the document.
Bear in mind a treaty is effectively a contract, and the Te Reo version was the one signed by the vast majority of Iwi. And even if they had signed both, my non-lawyer understanding is that international falls on the side of the one in the indigenous language in situations like this.
So, now its 2024, the agreement has to be interpreted to come across into English law language norms; and understanding of historical context and meanings of terms matters, that's why its a bit fuzzy but that's just the way it is. Act saying its not clear is more a sign that they reject the consensus that has emerged among experts than that there is no clarity.
The principles were clarified. Act just disagree with them so want to change the principles. Partly that's libertarian principle, but its also just race baiting electioneering. Changing the principles to what Act wants might remove ambiguity and make it clear but its done unilaterally and effectively reneges on the Crown's commitment to the treaty.
If you want to know why Maori might be angry about that, try telling your bank you have changed your understanding of your responsibilities on a loan document and won't be meeting their expectations anymore.