I agree. It's the provincial jury acts that dictate, to a large extent, how big the array is. You can pay jurors more because it's inconvenient.
When it comes to indigenous people, we have to recognize a fundamental.... They have a mistrust of the criminal justice system for obvious reasons, all the reasons you've stated. How do we encourage them to trust the system enough to want to participate on a jury?
I've selected juries in B.C. and the Yukon. The Yukon uses health records, so many more first nations people come. They all say they don't want to sit. Many people try to find reasons not to be on the jury. It would be partly through education and encouraging indigenous people to understand that they have much to gain by being on a jury.