Because it's using gdal, and the format argument is passed straight through, this does seem reasonable and future proof.
However, @pelson's right, we don't know what's going to happen with new raster formats.
Perhaps, as a compromise, the proposed ```export_geotiff()``` could call this function?
Perhaps it should also be renamed ```_gdal_export()```, as that's what it does.
That would leave us with these generalised gdal capabilities, whilst postponing the solution to multiple formats for another day.