Hi Andrew,
Greetings from Syncfusion support.
Based on your query we found that you are facing the performance issue when render the DatePicker component by using rowTemplate with loading large number of data’s in the Grid.
If the row template contains component like EJS-Datepicker then the control will be rendered in each and every row of the grid.
If we load 100 rows in one page then for each row the DatePicker component should be rendered (it take some time for each component rendered), so it will take some time which leads performance issue.
So to overcome this issue,we suggest you to reduce the page size ( i.e., 20 or 30) of the Grid to increase the performance.
Please check below sample for your reference:
Please refer the below documentation link for more information.
Regards,
Shalini M.