Function encode_refs_with_finishes 

pub fn encode_refs_with_finishes(
    meshes: &[InstanceMeshRef<'_>],
    collated: &Collated,
    finishes: &[[f32; 2]],
) -> Vec<u8> 

encode_refs plus each occurrence’s IFC-authored finish (#5984): finishes[i] is meshes[i]’s [metallic, roughness], NaN where unauthored, and a missing entry is unauthored. InstanceMeshRef is published with public fields, so the finish travels beside it rather than in it. Only a shard where some written occurrence authors a finish widens its records to trailing field 2 (stride 100, version 3); every other shard is byte-identical to encode_refs’s, so a model without finishes pays nothing. Read back with super::decode_instance_finishes.