Hi,
Flickering in path traced videos is caused by the denoiser that attempts to remove the noise generated in the path traced video. The denoiser is not as effective for temporal data, such as videos, as it is with images, resulting in flickering. Increasing the number of samples per pixel and max bounces for the Path Tracer settings should reduce noise and this flickering effect.
At this time, it is not possible to export and render color channels, but this is currently a planned feature for a future version of Twinmotion.
Best,
Raghib