What is the best way to check if the secondary ports are opening at the correct time. I heard that the car needs to be on a dyno, or the road to truly tell if they are correct.

No need to run the car on a dyno.... to see if they are opening correctly, put some grease on the little rods that move up and down, and then take the car for a "spirited" drive...when you get back home, and the grease was pushed or moved, that means the ports are opening. If you want to see when they are opening, you'll just need some trial and error...put some grease on the rod, take the car out, but dont go past 4K RPM...come home, if the grease moved, then they are operating normally, if not, keep moving up a few hundred more RPMs until the grease moves.....I'm sure there are other ways, but this one worked for me!