Some of custom files aren't used when trying to add them to the File Store. for example the formdesigner.js, at
view\webapps\usm\gwt\fdBase\scripts or
filestore\custom\gwt\fdBase\scripts.
When customizing, changes are only seen when performed directly on the original file, contrary to best practices for most Service Catalog customization
Release : 17.3
As documented at
https://techdocs.broadcom.com/us/en/ca-enterprise-software/business-management/ca-service-management/17-3/building/building-ca-service-catalog/modify-xsl-xml-javascript-and-image-files.html
Only the javascript files under explorer\scripts can be modified in the customization folders. The gwt structure is too tightly combined, including through 3rd-party plugins we don't have full control over, to allow for use of the file store.