Route: Couple of options.

  1. PDP route, ending in the bottom of the elevator.
  2. (Might be faster) Place the blue portal on the ground, jump through and AFH to the portal gun. Grab it while continuing to AFH into the opposite wall and place an orange portal to come out of your first blue portal. Clipping glitch in the upper-right hand corner of this area, placing the portal underneath the end elevator. Edge glitch into the bottom of the elevator.

I’ll test the second one with timescale later. I think it would look especially slick, but it might not actually be faster.