Here is my current config in FOG, using latest gparted zip file (as of Dec. 2021):
kernel http://${fog-ip}/gparted/vmlinuz initrd=initrd.magic
initrd http://${fog-ip}/gparted/initrd.img
imgargs vmlinuz boot=live union=overlay username=user config components quiet noswap toram=filesystem.squashfs net.ifnames=0 nosplash fetch=http://${fog-ip}/gparted/filesystem.squashfs
boot || goto MENU
Gparted boots fine. 