Hi Will,
Thanks for using Syncfusion Products.
You can achieve this by changing the NumberFormat of PercentEdit cell in CurrentCellStartEditing and CurrentCellEditingComplete event handler. We have created a sample for these things. Please find the sample for this in the following location.
Sample :
http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=PercentCell2042197549.zipPlease let us know if you have any queries.
Thanks,
Thangaraj T.