I decided to merge one of my previous ideas (Parliament streetcar) with a couple other proposals to come up with this.
The 501 Queen route now ends at the 2150 Lake Shore development, here labeled as Humber Bay, in the streetcar loop that connects to the proposed GO station. It continues eastwards through its present-day route to the Scarborough border. A new route, potentially replacing the 509, now covers the stops west of Park Lawn, allowing for a quicker ride to the South Core. It then continues through the underground segment below Bay and Yonge, maybe or maybe not stopping at Queens Quay or Union, before continuing onto the East Bayfront route and up Parliament to Castle Frank Station.
Also marked along the route are all of the streetcar stops, both major and minor, however I did make some changes:
West of Royal York: Stops at 28th, 15th, and 5th Streets were removed. 28th and 15th Streets do not have traffic lights anyways.
Royal York to Humber Bay: Stops at Norris/Hillside, Superior, and Louisa were removed.
Humber Bay to Kingsway: The stop north of Silver Moon and the stop at Jean Augustine Park are served by the 509 branch only, while the current Humber Loop is served by the 501 only. Kingsway is served by both lines.
Kingsway to Dufferin Street: Windermere is served by the 501 and Ellis by the 509 to reduce stopping frequency in Swansea without compromising service. The 509 splits at Colborne Lodge and stops only at Budapest Park and Jameson Avenue before Dufferin. Stops at Triller and Dunn were removed.
Queen from Dufferin to Parliament: Sudbury is not shown here but IDK how much of an obstacle the rail bridge is to the Dufferin stop. Stops at Abell, Shaw, Peter/Soho, St. Patrick, York, Victoria, and Ontario were removed.
Harbourfront from Dufferin to Queen: Follows the existing 509 route, minus stops at Fort York and Billy Bishop. East of Bay, the streetcar stops at Freeland, Lower Jarvis, Lower Sherbourne, and Small before turning onto Parliament. On Parliament, there are stops at Mill and King.
Queen east of Parliament: Stops at Carroll, Saulter, Logan, Pape, Alton, and Elmer were removed. The stops on the Downtowner/Kingston branch were inaccurate from the get-go, I think, so just ignore them. I'm not sure if any of these stops have already been removed or not.
Most stops have a larger buffer between them, but in some areas I kept trios of closely spaced stops because the middle one serves a point of interest (e.g. Niagara and the St. Nicholas church, Sackville and Trefann Court/Regent Park). I do look forward to the day where the streetcar stops in Toronto aren't so close together that it's a pain to draw them all for a single line, let alone the whole system.