Is cobus still needed for OSS at YYZ (coming from USA)? Any Nexus machines yet?

Seems that waits at domestic security at YYZ outside of rush periods are workable so don't want to get trapped in bus limbo (tightish connection but easily walkable in 20-25 minutes through regular customs with NEXUS and security with NEXUS or priority.

My first thought is always exit and come back in whether in LHR, YVR or YYZ. Am I wrong?