In an effort to move to a more well-adopted international source, we'll replace the existing Natural Earth data with data provided by the UN.

https://github.com/etpinard/sane-topojson is used under the hood by Plotly for GeoJSON management.

Here is a draft PR to add the UN GeoJSON file to that repo: etpinard/sane-topojson#44

The UN data is sourced from: https://geoportal.un.org/arcgis/apps/sites/#/geohub/datasets/d7caaff3ef4b4f7c82689b7c4694ad92/about

FieldMaps could also be a strong alternative: https://fieldmaps.io but we are opting for a source managed by a central, governing entity.