I have updated my post #544 with step by step tutorial Sure, you can do it manually too, mount image, mount registry, import registry, save image, rebuild WIMs and build ISO
Somebody else realised that now Compact is applyed automatically on new installations? (install from boot) i think the installer determines the free disk space and applyes CompactOS on small disks (e.g a 120gb SSD) on larger hdd (e.g a 500gb hdd) it is not necesary and is not applyed... Spoiler