Agreed. As you can see in the above image, Woodbine is closer than Malton, if we're planning on any future underground LINK II tunnel.I was comparing Malton station to CodeMonkey's theoretical station between Airport Road and Torbram Road.
A very fast high-performance underground people mover can move you from Pearson Rail Hub to Pearson Airport (2.5km) in a mere 2 or 3 minutes. Why spend $5 to $20 billion on an underground HSR tunnel that requires long, gentle curves?
There are new high speed peoplemovers today that bring you the whole distance from Pearson Rail Hub at Woodbine, faster than today's slow LINK between Terminal 1 and Terminal 3!
Besides, UPX spur might need refurbishment by 2050...