Borescope mystery

Recently borescoped my 912 ULS during sparkplug change. Engine is running great nearing 800 hours, no issues, and has excellent diff compression all around. Plugs all fine. Not making any metal. A few light scuffs or scores on cylinder walls, nothing major, good crosshatch showing everywhere. But #1 is showing an odd line on the cylinder wall that's not a straight line, it makes a curving 30degree right turn as it goes toward the upper cylinder. First glance it looked maybe like a crack, but I've never heard of a cracked Rotax cylinder, and if it were, oil would be leaking all over, I think. Again, the crosshatch appears normal here as well, and it almost looks like the line is showing through from under the cylinder wall coating and crosshatch. I wonder if anyone else has seen one like this. No logs or other evidence that the engine has been apart since it left the factory. I'm stumped. Thanks.