The Xojo IDE Build scripts changed with Xojo 2020r2, with the 2020r2.1 update Xojo have provided the functionality that enables the AW4 scripts to fire on build after all the architectures have been built and assembled.
The Scripting page of AW4 has been updated to make it easier to integrate the new scripts into your Xojo workflow. Simply follow the directions that are provided directly on the page.