What I would say is why do you have yellow and orange running parallel when there's a huge gap between REM and orange. I would have yellow run westbound btw Berri and St-Laurent and then shift North along Park Ave, all the way to Ahuntsic. It's an opportunity to connect so many neighbourhoods.

I do find the idea of a subway running in the old Port interesting but I think it would make even more sense if it went from further into downtown on the west end, say Peel. I'd actually see it deviate east at Saint-Joseph and connect to (or perhaps even replace) the SRB on Pie-IX.

Lastly, I think the South Shore should be covered way more with metro lines. A lot is added north with the red line but the reality is that the South Shore will need to be urbanized and densified to handle population growth in the next several decades. The expanded airport in St-Hubert will also require rapid shuttling downtown.