Hi Adrian,
Thank you for your update.
The GridGroupingControl the ResizeToFit in RowHeights can be done through a CustomEngine which calculates each rows. Please try using CustomEngine of resizable rows to achieve the ResizeToFit heights behavior in GridGroupingControl. If you want WrapText behaviour in GridGrouping control, then please try using WrapText and AllowEnter property in QuereyCellStyleInfo event and RezizeToFit method in TableControlCurrentCellChanged event to achieve this behavior in GridGroupingControl.
Please refer the sample in below link:
http://files.syncfusion.com/support/samples/Grid.Windows/Forums/WrapText.zipThis sample demonstrate the Wrap Text behavior in GridGroupingControl.
Let me know if you have any queries.
Regards,
Lingaraj S.