To export GoPro CineForm footage, the frame width must be evenly divisible by 16 and the frame height by 8. Dimensions that do not meet these requirements are automatically rounded to a valid value.
For example, GoPro CineForm 2.7K video content cannot be exported at its native resolution because the height, 1524, is not evenly divisible by 8. So, the export dimensions are rounded to 2704x1528. As a result of this change in dimensions, 2.7K content cannot be smart-rendered.
Therefore, it may be necessary to upscale or downscale the dimensions of your output to conform to industry standard dimensions. For example, with 2.7K footage, downscale the frame size to 1920x1080 or upscale to 3840x2160.