Exactly, I know that complete process is like this: 1. Download UUP Dump 2. Use UUP Converter only to create ISO with install.wim (Base .1 with no updates). 3. Use W10MUI to add languages (including to WinPE files, which is another download to make) to the Base .1 ISO 4. Use W10UI to update the base ISO. So, this process could be reduced a lot if UUP Dump supports multilingual creation. Because if UUP Converter (by @abbodi1406 ) supports it, it would generate in a single pass a multilingual and updated ISO (without the need for W10UI or W10MUI).