This may sound stupid but how does one increase their 'edge angle' when turning? Like what exercises should I do to have this locked down?
It tends to come from more dynamic riding, where you are using more lower body movement independent of your upper body, which allows you to dig the edge in harder, therefore allowing the upturned edge to reach a higher angle off the ground.
watch some of these:
Intermediate Snowboard lesson: Linked Turns - YouTube
Dynamic Skidded Turns - YouTube