You've made some good points - I'll add, the crown is represented by however jurisdiction over certain things has been split amongst Canadian Federalism, where provinces as you say have jurisdiction over certain things like education and healthcare.
Also there are the Natural resources = province. I assumed that this is what we've been talking about this whole time...
And I'll say it again - not all treaties are the same and Ontario was a signatory to Treaty 9!
The modern treaties in BC are negotiated by Canada and the province as another example.
The old treaties are typically not being "renegotiated" as such in mining talks and so that's why I say that the Feds don't actually need to be at the table. Look at agreements with other provinces such as Alberta and Sask. where the Feds aren't a factor with FN natural resource deals at all. The provinces just consult and pay up once agreement is had. Sask is actually a great example for "getting it right."
If we make this about the treaties overall with the Feds, then FNs turn the conversation away from a natural resources sharing negotiation into something much more complicated.
For all of our sake, let's stay focused on the immediate deal at hand and what it means to have reasonable accommodation for FNs in this repect.