Create Modification Packages
AdminStudio 2023 | 25.0 | MSIX Editor
A Modification package lets you customize your main MSIX package. Modification package is equivalent to a Transform (.mst) for an MSI package. The key feature of a modification package is that it is not tied to a specific version of its main MSIX package, which give you an advantage to create a modification package once and use it for all the current and future version of its main MSIX packages, unless you want to add any additional customizations.
Modification packages have the same extension as MSIX packages but contain only files and registry keys. Modification packages cannot be installed on a machine independently. The main MSIX package must be already installed on a machine to install its modification package on the same machine to apply customization successfully. When a modification package is installed, Windows will see its content as part of the same container as that of the main MSIX package thus treating every file and registry key in a modification package as part of the its main MSIX package.