JED 1.6.0+ - Custom full-height cave world

{
    "dimensions": [
        {
            "dim": 123,
            "normal_biomes": true,
            "dimensiontype": {
                "id": 123,
                "name": "Cave World",
                "keeploaded": false,
                "worldprovider": "WorldProviderSurfaceJED",
                "require_exact_match": true
            },
            "chunkgenerator": "ChunkGeneratorFlatJED",
            "worldinfo_onetime": {
                "generatorName": "flat",
                "generatorOptions": "3;1*minecraft:bedrock,254*minecraft:stone,1*minecraft:bedrock;1;caves,decoration"
            },
            "jed": {
                "CanRespawnHere": false,
                "RespawnDimension": 0,
                "SpawnPointSearchType": {
                    "type": "cavern",
                    "min_y": 10,
                    "max_y": 240
                }
            }
        }
    ]
}