don't like the middle park. It'll be dark and represents an unnecessary break in the streetwall.
From Streetview, a look at the prospective open spaces (current condition) and potential for light.
Park at eastern end of site: (looking south, from the north end of the site)
(now looking south, from the southern end of the site)
Based on the above, there is sufficient potential sunlight, providing that no development of the Toronto Hydro building occurs, and any development on its parking lot is very short. There is no sun from the east or west at this location, except any small amount that might occur through the mid-block park/pops.
Any building on the south side over 3s will slowly remove all remaining light from the space as it increases in height, the shadow going further and further north.
*****
Mid-Block Space
Very limited sun from the east, will crest the adjacent apartment in the brighter months, but not that much:
The western view, from the Yonge Street side:
Halo will block a lot of light.
I'm inclined to agree with
@innsertnamehere that any mid-block mews will be challenged for light.
It could be an interesting space still, providing wind can be mitigated; but may require extensive artificial light even during peripheral daytime hours (prior to sunset and after sunrise)
For reasons that defy logic to me (maybe the shadowing will break differently than I think) they've proposed a Ginko in that middle space; Ginko's are a full sun species.
Curiously, they've also proposed Canada Yew, which is very much a deep shade species............