Thanks for the report. So, in Windows 10 1809 (in this case, LTSC 2019), the "Reset this PC" feature won't work if "ResetBase=2" is used. Some remarks about it: "ResetBase=1" will have the same issue in Windows 10 and would be very possible to have it in Windows 11. For critical mission environments, where the maximum stability for the long term is needed, the "ResetBase" option must not be used (the default value, "0"). It's not about the "Reset this PC" (buggy) feature, but it's because some future updates, imaging processes, or other kinds of IT management could fail because of the extreme compression and deletion inside the WinSxS folder. "CleanUp" option is safe to use. It's likely that in Windows 10 builds 19041/2/3/4/5 and Windows 11 (from 21H2 to 26H2), the "ResetBase" ("1" or "2") option could bring the same problems. If building an updated Windows 10/11 ISO (UUPDump + UUP Converter), using "Create ISO with install.wim", "Integrate Updates", and "CleanUp" results in almost the same final size as the official monthly Consumer/Business ISO, it is much better to just download the official ISO instead of doing this whole process. Now, if instead of creating an ISO with "install.wim", you create an ISO with "install.esd". The size reduction could be worth it and be preferable to the official monthly ISO.