I wanted to switch to Debian 13 but couldn't assign a machine yet, so I needed a way to keep customizing my OS while still being able to move to any machine later. Research showed that there is a tool called Refracta Tools (Refractasnapshot+Refractainstaller) exactly for this. However, it would produce an unbootable machine for me every time. So, with some help of an LLM I got down to fixing and improving refractainstaller CLI and GUI. The end result: few clicks in the GUI to automate BTRFS subvolume partitioning on an empty drive and to install your Debian 13. Sharing here if anyone finds it useful.