Probably in the fantasy land, but if it can be funded then I would try something like this:
View attachment 408295
Assumes that Sheppard is converted to OL type technology, or another kind of mini metro. Then it can be combined with Eg East. It would run elevated along Eglinton, Kingston, and Mornigside. Segment next to Hwy 401 would be at grade, with a bridge over Neilson.
The dashed lines mark two possible ways of connecting to Sheppard: either via STC, or via Sheppard & McCowan. That segment might be partly tunneled.
This route would help with the Eglinton demand, and at the same time, connect Sheppard with Lakeshore East GO, and connect both Sheppard and LSE GO to UTSC and to the Centennial Progress campus.