Not a necessity nor deal breaker for me if not ideal to implement. More of a nicety.
Use case:
Being able to have the Flyway toggled on over top of the Sectional ahead of time, still being able to reference where you are at on the Sectional as you approach and enter the Flyway Chart. As opposed to switching to the Flyway Chart the moment you enter the area of the Flyway Chart. Just giving a little more S.A. being able to look ahead at the Flyway while still located outside of the Flyway on the Sectional.