We should really only need one geometry. I initially wanted to try exporting both edges to make it easier but this will OOM on a planet scale due to how FGB indexes are currently built (RAM needed initially scales with number of features).
To combine the edges we will need to re introduce the opposite edge fetch, write access based on the forward / reverse perspective consistently, and write two edge ID fields.
We should really only need one geometry. I initially wanted to try exporting both edges to make it easier but this will OOM on a planet scale due to how FGB indexes are currently built (RAM needed initially scales with number of features).
To combine the edges we will need to re introduce the opposite edge fetch, write access based on the forward / reverse perspective consistently, and write two edge ID fields.