Meta decides delivery across Facebook and Instagram from one auction - so splitting them into separate "channels" burns money. What actually changes on Instagram is the creative: Reels-first, native-feeling, built for sound-on.
Cutting Reels-first variants fast is the whole game - turning one winner into sound-on Stories and feed cuts without a full edit suite. Vidfly is one of the AI tools we curate for making native-feeling Instagram video at testing volume.