Cura/resources/extruders/builder_premium_medium_rear.def.json

{
    "version": 2,
    "name": "Rear Extruder",
    "inherits": "fdmextruder",
    "metadata":
    {
        "machine": "builder_premium_medium",
        "position": "0"
    },
    "overrides":
    {
        "extruder_nr":
        {
            "default_value": 0,
            "maximum_value": "1"
        },
        "extruder_prime_pos_abs": { "default_value": true },
        "machine_extruder_end_pos_abs": { "default_value": true },
        "machine_extruder_end_pos_x": { "value": "prime_tower_position_x" },
        "machine_extruder_end_pos_y": { "value": "prime_tower_position_y" },
        "machine_extruder_start_pos_abs": { "default_value": true },
        "machine_extruder_start_pos_x": { "value": "prime_tower_position_x" },
        "machine_extruder_start_pos_y": { "value": "prime_tower_position_y" },
        "machine_nozzle_offset_x": { "default_value": 0.0 },
        "machine_nozzle_offset_y": { "default_value": 0.0 },
        "material_diameter": { "default_value": 1.75 }
    }
}