When creating encapsulated assertions, they have been put into a special folder called "/Encapsulated Fragments". What is the best option to have them migrated to a new gateway independent of them being used in other policies.
Please use the --encassAsPolicyDependency flag.
It will export the encapsulated assertion without the need for it to be used in a policy. So the command could look like this:
GMU.bat migrateOut --argFile test.properties --folderName "/Encapsulated Fragments" --dest "D:\Encap\Testing" --format directory --plaintextEncryptionPassphrase <xxx> --defaultAction NewOrUpdate --plaintextPassword XXXXXX --encassAsPolicyDependency