Currently updating an Arcade symbology expression wipes out all symbol configuration and overwrites all the symbol classes.
If there was a checkbox option for existing symbols and classes to be locked, with any new values returned to be added to the 'Other' category after the expression is updated, it would save time. In conjunction with the awesome new option to add values to the legend, it would also allow symbols/values to be preconfigured , with an expression written afterwards to return those values.
