And that's all irrelevant, because the end result is you have another instance of a program operating on a different file. The rest is unnecessary, and it has nothing to do with systemd or Wayland. You could use the exact same binaries running in a chroot or any other form of container to achieve your isolation, and the isolation isn't even needed
because they are different files.
Your use-case of running multple different versions of the software is not relevant to the thread. Your hatred of systemd, Wayland, or any other piece of software is not relevant to the thread.
In the current state of KiCAD there are two simple methods to gain a limited second view of a PCB or schematic:
- Disable autosaves, remove the lock files, and run a second instance (dangerous).
- Make a second copy of the project and open it with a second instance of the tool (safe enough).
Your method is the second with additional complications fueled by other specific requirements and/or your own desires.