The Batch editing is client-side edit mode and any full postback will clear all changes in the grid and will close any cell/row that is currently in edit mode.
The only thing that I could suggest for achieving such functionality is to prevent the postback of the buttons and handle the client-side click event, where you could use an external RadAjaxPanel for example for firing custom command. The retrieved from the server-side information could be passed through a HiddenField control. However, I would personally recommend that you switch to server-side edit mode if you need such server-side validation.
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