I'm actually not real sure what the ask is here, as the core bits of functionality seem to still work with systemd-boot based images. Presumably if there is a way to manipulate the BLS entries in the images, then that functionality would need to be added, or simply creation of images with systemd-boot rather than grub. Opening as a placeholder per fedora-dev Reproducible: Didn't try
This bug appears to have been reported against 'rawhide' during the Fedora Linux 39 development cycle. Changing version to 39.