Function parquet_metadata_key 

pub(crate) fn parquet_metadata_key(cache_key: &str) -> String

The flat Parquet metadata entry (the X-IFC-Metadata header) for a request cache key. THE definition of that suffix, for the same reason as above.

NOT keyed by layout, and not versioned alongside the geometry: it holds the metadata header, whose shape #3888 did not touch and which is identical for both layouts of the same file. A hit needs the geometry entry too, so the layouts still cannot cross-serve.

v5 with #4653: the header’s metadata.georeferencing gained the IfcMapConversionScaled factors, and a v4 header replays them as 1 (see json_response_cache_key). The geometry keys stay put: a miss here re-parses, and the parse rewrites the geometry entry beside it.