They are, as you point out, very similar questions or related questions. To my mind, the answer goes back to how we design an effective electoral system for the Senate.
Let me start with the case of Ontario, which is an interesting one.
The proposal recommends a single transferable ballot. If we think of Ontario as being a single constituency with 24 senators running for election at the same, all on the same ballot, it seems to me that we lose the opportunity to build in the chance for different forms of minority representation.
Let me step back just a bit.
The Australian Senate uses a similar kind of ballot. One of the interesting things in Australia is it means that you can win a seat in the Senate with about 6% to 7% of the popular vote if you're running in a particular state. That's actually opened up the opportunity for a variety of minority group representations within the Senate that cannot occur within the lower house in Australia, where it's basically like our House--a slightly different ballot.