By default, Atrium will check menu availability again at launch time, even after the menu items have been previously validated and loaded. This is useful if we expect the authority to a menu option to change on the fly. This check also calls the PUIATEXCHK exit program, which allows a customer to reference their own menu navigation settings to control this feature. However, the extra processing has an impact on performance and it may be desirable to skip it, which you can do with this option.
Atrium["skip launch check"] = true;