For building steps, generally follow the Pengwin building guide here.
.diff:
To create the install.tar.gz go to the project: https://github.com/WhitewaterFoundry/fedora-remix-rootfs-build create-targz.sh must be run on an existing Fedora Linux build instead of Debian.
Because the building process bind-mounts /dev within the newly created chroot, this must be run on a full Fedora install (bare metal or virtualisation, NOT a WSL install).