I wonder if it would be possible to continue the long hallway that currently goes to Place Bonaventure. Currently, it ends at the escalators up to Place Bonaventure, but it also continues straight to a cleaning office for the STM. This could be taken over turned into the hallway, and continue straight under the tracks of Gare Centrale, until reaching the REM. This is where there can be steps/escalators and even elevators up to the platform. This would fully avoid entering Place Bonaventure, would connect directly to the metro, and be accessible with just one elevator down to the metro, instead of 3.