I agree; the routing around (Alt. A1/2) is a bit intrusive into surrounding land.
Alternative A2:
Since Moodie is already elevated over the 417, and there are no driveways off it in this area, the elevation can be maintained farther north to allow the Transitway to pass under it. Personally I would like to see the new Moodie structure built sooner rather than after the buildings around there get filled with new workers. Also, with all the interim work that needs to be done
and then un-done, it might be less expensive just to do the final configuration from the start.
Personally, I still prefer my plan to move the 417 ramps permanently.
If the bus loop wasn't needed, I would suggest that there would be local bus stops on Moodie, above the Transitway Station below, and a temporary loop be added west of the Moodie structure.
To build this is easy: The south-bound lanes of Moodie from the current 417 ramp intersection to the current bridge are closed and the traffic shares the north-bound lanes (one lane per direction). The slope from the intersection south is increased, the extra bus-lane is added, and the walls of the west half of the new structure are bored/dug and pored (without digging out the muck between them). Then that half of the new structure's deck is cast in place, using the undisturbed ground between the walls for support. Once that side of Moodie is at the correct elevation, the new west-bound ramp to the 417 is built. Both south-bound and north-bound traffic is moved over to share the newly raised south-bound lanes. There will be one through-lane per direction and a center turn-lane for north-bound vehicles to get to the new west-bound 417 ramp. The north-bound lanes are then raised and the same technique (cast support walls and then cast deck in place) is used for the east half of the new Moodie structure. Those lanes are then opened. Since the circular S-W Ramp is no longer in use, it can be removed, the SWM pond can be modified, and the new west-bound off-ramps can be built. At this point the roadway is configured and working as planned so the Transitway underpass can now be excavated under the new structure.