Structured numpy arrays, xarray and netCDF(4)

I'm trying to use xarray as the underlying container for some data processing tasks. Part of the pipeline includes processing from non-standard/easily readable formats (e.g. ROS messages) to standard formats, e.g. netCDF(4). The data I tend to be working on is time series data that is structured, which maps pretty well to structured numpy arrays using dtype manipulations. And xarray lightly wraps numpy, and provides netCDF as a backend. However, the xarray implementation doesn't really expose this capability, supported in netCDF as 'compound data types', and in fact it fails when you try and write such a DataArray/Dataset to file (at _nc4_values_and_dtype).

So the question is, is this a reasonable feature/expectation from xarray (and thus you're receptive to contributions), or is this outside the goal/purpose (I should roll my own/use pandas/etc)?

Start by reviewing xarray/backends/netCDF4_.py, especially _nc4_values_and_dtype, and the linked NumPy structured-array and netCDF4 compound-type documentation. Determine whether structured arrays and compound data types fit xarray's intended scope; a contribution would need an agreed behavior and validation that DataArray or Dataset values can be written correctly.