I wonder if at any point someone will just give up admit it was fucked from the moment they decided to keep the wrong type of train for the service they should be running, and just buy the correct type of train. A proper metro train like every other other city trying to run a mass transit line with high frequency. Ideally something with radial seating, digital signage and wayfinding. Some stations in Japan even have info above where the doors will be in the station showing how full each car is.
We'd need to rebuild all the current stations to be high platforms, and finish the under construction stations to also be high floor. It's a lot of money sure, but no one will care in 50 years, they will just be thankful to have an amazing metro connecting the entire city. The Shinkansen went 2 times over it's inital budget, but no one gives a crap now a days, they're just happy to have it.
We're the capital of Canada, we need and deserve better than this shitty system.
Oh, and add platform screen doors to all the above ground stations, partly for safely, partly for weather, make a huge different to quality of the service.