Don't forget that the Line 1's Eglinton Station (and Eglinton West/Cedarvale Station) is still in operation. So they could open up Line 5's Eglinton Station underground, while still working on the above. They could use the current Line 1 entrances at Eglinton. Trains have already been operating in testing mode on Line 5 through both Cedarvale and Eglinton Stations.
Take a ride on the Eglinton LRT line from Laird Station to the Eglinton Maintenance and Storage Facility!
The final piece of track for the Crosstown was laid in fall of 2021 meaning light rail vehicles are now able to
test on the full length of the line between Mt. Dennis and Kennedy. The special wraps are no longer in use as a result. The two pairs of LRV's I caught were LRV 6261 coupled with 6262 & LRV 6249 coupled with 6224.