I think that this design is really a wasted opportunity to connect Exhibition with the city to the north.
The station should basically be a very wide bridge north to south, over the tracks and under the Gardner. Forget about pedestrian tunnels under the tracks. Stick a roof on it and elevators, escalators down to the tracks on either side of the bridge. Ideally, you would lower the tracks in this section so you don’t need to go up before crossing but $$$.
It needs to be able to handle crowds from sporting events and the CNE.
It’s a pretty common design in Japan except there would also be a department store. This is a photo I found of Saitama Shintoshin station. It’s open on both ends.
View attachment 453441
Do whatever you want with the roof.
Then take Pardee Ave and pedestrianize it, add patios, etc. and link the Ex with Lamport Stadium.
With BMO field, the Marlins rink, Lamport, the Raptors facility, the Indy, really lean into the area as a sports hub and give it an identity. Convert some of the existing buildings to community sporting uses - ice pads, gymnastics facilities, a ninja warrior gym, rock climbing, skate boarding. Build new fill in buildings for whatever can’t be converted while burying the parking underneath.