Upload of Terrain tiles to Ion does not work

Hello, I’m trying to upload terrain tiles that work with cesium-native when serving from a local directory. Ion importer recognizes the layer.json (or tileset.json in another try) but fails to run the tiling pipeline while it only needs to copy the files. According to Tiler Data Types and Formats – Cesium table import of zipped Terrain tiles should be supported. Is it correct that there is no option for Terrain as kind of data but only 3D Tiles?

Hm ok I see the tiles need to be put into an undocumented .terraindb sqlite container. Do you have a minimal example terraindb from which one could investigate the schema?