WimBuilder2 is an open source lightweight editor for wim file. but be powerful, fully customizable and easy to use.

Based on script technology GUI framework, user-friendly and infinitely expandable. Can run on your desktop and can be used in Windows, WinPE (Windows Preinstallation Environment).
It will use the Dism command to automatically mount the wim file and the system registry, The built-in rich macros help you quickly customize and modify wim files.