JP,
We greatly appreciate your feedback and dedication to improving our product.
Currently, the DataGrid allows adding new rows only at the top or bottom of the entire data list, and not within individual grouped sections. This limitation is intentional due to the dynamic nature of grouped data:
When a new row is created, its inclusion in a particular group depends on the value given for the grouped column. If the value for this column does not match the current group, the row will be automatically reassigned to a different group, resulting in the key (group assignment) changing. This ensures data consistency and integrity but means a row cannot reliably be added “within” a group from the UI.
Additionally, in our review of several leading industry-standard DataGrid controls, we found that they also do not support adding new rows within grouped rows, for similar reasons related to data structure and grouping logic.
For these reasons, we are unable to consider this feature at this time. Thank you for your understanding and continued support.