Setting this property to true allows you to load existing XLS/XLSX files, modify the values in some cells, and save the file preserving the formulas. This is the default setting.
Setting this property to false causes the component to remove the formulas in the book when it is loaded. Saving the file in this case will retain the last calculated values but will remove the formulas.
Assigning any value to a cell will clear the formula in the cell.