This might need to wait / could be enabled by the feather v2 (ARROW-5510), but thought to open a specific issue about it: do we want to support saving metadata in feather files?
With Parquet files, you can have file-level metadata (which we currently use to eg store the pandas_metadata). I think it would be useful to have a similar mechanism for Feather files.
A use case where this came up is in GeoPandas where we would like to store the Coordinate Reference System identifier of the geometry data inside the file, to avoid needing a sidecar file just for that.
In a v2 world (using the IPC format), I suppose this could be the metadata of the Schema.