Thanks for using Syncfusion product.
By default, Spreadsheet does have the support to change the default paste option using DefaultPasteOption property. Please refer the following code example.
Me.spreadsheet.CopyPaste.DefaultPasteOption = Syncfusion.Windows.Forms.Spreadsheet.PasteOptions.Value
To avoid the paste popup showing when press the ctrl+v, you could disable the AllowPasteOptionPopup property. Please refer the following code example.
Me.spreadsheet.CopyPaste.AllowPasteOptionPopup = False
Also, you can set the default paste option using PateOption property in Pasting event which is only paste the value based on the PasteOption value. Please refer the following code example.
AddHandler Me.spreadsheet.CopyPaste.Pasting, AddressOf SpreadSheet_Pasting
Private Sub SpreadSheet_Pasting(sender As Object, e As SpreadsheetPastingEventArgs)
e.PasteOption = Syncfusion.Windows.Forms.Spreadsheet.PasteOptions.Value
Please refer the below UG link for programmatical implementation for Cut/Copy/Paste operations
Please let us know if you need any further assistance on this.