Conditional formatting is used to change the appearance of the pivot table value cells based on specified conditions, such as background color, font color, font family, and font size, and we have the "applyGrandTotals" property to include or exclude conditional formatting for the grand total values.
According to the customer's requirements, a checkbox option for enabling/disabling the "applyGrandTotals" property through UI interaction for each value field should be included to the Conditional Formatting dialog UI. This checkbox option allows the user to specify whether the specified value field holding grand totals should be considered when applying conditional formatting. Please find the example screenshot for reference:
Screenshot of Customer Requirement: