You can access the texture containing layer data via the onUpdate lifecycle method: XR8.LayersController.pipelineModule() | 8th Wall.
Although, a more straight-forward way to avoid the banding effect could be to prompt the user to rotate their device and classify pixels before displaying AR content.
For some background on Sky Effects, camera pixels are either categorized as “unknown”, “sky” or “not sky”. “Unknown” pixels are considered “sky” until they are able to be classified - resulting in the banding you’ve noticed near the edge of the device as you move it around.
You could guide the user to rotate their phone 180-360 degrees before revealing sky content in order to classify unknown pixels before displaying content in the sky to avoid this effect.
I have a filed a feature request with our engineering team to allow this behavior to be configured by developers (i.e. classify unknown pixels as “not-sky” instead).