Channeling refers to directing the airflow in the sail, deeper channels (the billow in the sail) affect how the air moves as it hits and leaves the sail.
How does it affect the back tricks? Well, the sail certainly does “give in” when air hits the back, but you tell me how it works...
As for new dual lines, YES, hoping to roll out some new ones under Kite Forge sometime next year - we already have the Kaiju indoor kite with plans in the works for a trickier indoor model and a “true blue” trickable team kite (balance of trick and precision)... Stay tuned.