Here's my rough concept for Phase 3 using the Beachburg & Smiths Falls subdivisions:
Two new lines follow rail corridors almost exactly, except I had the line from Kanata/Nepean deviate to Hurdman instead of terminating in Tremblay. Avoids using up VIA's platforms. I also combined Confederation & Heron stations--how exactly, not sure, but I would like to see that. The SE Transitway would remain; it and the Kanata line would parallel.
Between Confederation Heights & Bayview the line would be double tracked. Both it and the Barrhaven line would have 8 minute frequency allowing for combined 4 minute frequency at Carleton, Carling, and Gladstone.
Yes, I removed the Trillium Line to Riverside South and put to the Airport instead. I honestly think Riverside South is better served by a transitway extension down the old N-S LRT corridor instead, it allows for direct service instead of an awkward transfer at Bowesville. And yes, I did plan for the Baseline spur to short turn at Tremblay. Orleans doesn't need 90 second service.