I'd like to see more coverage, but not sure there is enough capacity for 2 branches, given that the OL trains will be smaller than the TTC Line 1 and 2 trains.
Perhaps the Humber Bay Shores will be fine with only getting every 2-nd train. Not many feeder buses there. But the branch that goes up Dufferin or together with the Kitchener line, would see lots of transfers from Line 2, from ECLRT, and from numerous bus routes. Doubt every 2-nd OL train would handle the demand. On top of that, Metrolinx wants the OL Libverty Village station to intercept some of the GO riders and thus relief the Union station.
I'd rather extend OL along the west shore only, avoiding tunneling and going either elevated or at-grade in the rail corridor. Perhaps 1-out-of-2 or 2-out-of-3 OL trains would actually serve the west shore, the rest would short-turn at Liberty Village and provide the relief capacity that Metrolinx wants there.
And for the west-end-to-downtown line, I would select a completely new route. Perhaps going across downtown under Dundas, then either up Dufferin or with the Kitchener line.