Hi Melinda,
Thank you for your interest in Syncfusion products.
You can check the existence of Group (option button) using the code snippet given below:
sheet.Range[2, 2, 4, 4].IsGroupedByRow;
sheet.Range[2, 2, 4, 4].IsGroupedByColumn;
Also using our latest version (v7.2.0.20), you can read and write checkboxes. Please refer to our documentation in the link below:
http://help.syncfusion.com/ug_72/xlsio/CheckBox.htmlPlease try this and let me know if you have any questions.
Regards,
Geetha