Just looking at the maps ... what if the line is routed first under Eglinton, then under Brimley (placing the curve under the Scotiabank parking lot), up to Lawrence.
Then curving east, and surfacing in the Gatineau Corridor. The wires may be shifted 30 m to the north, making room for the "Lawrence East" subway station.
Highland Creek would be crossed on a bridge. Then going under again, curving north and continuing under McCowan, following the current preferred route.
Benefits: Lawrence East station restored, and should be affordable due to being on surface. In addition, the tunnels may be somewhat cheaper as most of them will be shallow.