Working in Emergency Management, there is lots of data that is aggregated at a local council level and available as a web CSV, which is owned by other agencies. Because this data does not have coordinates, it does not auto-update and I cannot join it directly to council area boundaries that we host. The only way around this is to create scripts, but this requires downloading the data and then changing data ownership which is not ideal. It would be great if you could dynamically join your hosted feature service to the web csv, and allow it to update when the other agencies update their data.
A similar problem has been posted as a question by the ESRI community here: https://community.esri.com/t5/arcgis-online-questions/dynamic-join-between-web-csv-and-hosted-featur...