I was very disappointed to learn when I got my note 9 that I am unable to switch between lenses when using either the Filmic pro camera app or the Moment pro camera app. Why on Earth would you stop 3rd party camera apps from being able to switch lenses? it's a camera
The Note 9 is unique with its two apertures (I assume that's what you mean by "lenses"). For an app developer to include a special aperture-switching button just for the Note 9 would be unnecessary work since most Android phones don't have that feature.