I'm trying to use the Extended Data Table component with the rich:columns and rich:columnGroup but it seems that they are not supported because the component cannot coordinate well the limits of the header columns and its correspondings table cells.
You can test applying the same structure used for the dataTable example (components demo).
Are these features planned for the near future?
rich:columns are supported, can you please post related code for the investigation?
Handling for rich:columnGroup in rich:extendedDataTable is not currently supported, and is not planned for the nearest release.