HELP repacking game with update pkg

I'm trying to repack the Dying Light Enhanced Edition devmenu pkg with the base game pkg using duxas ps4 repack manager everything goes fine to my knowledge. The output folder has a new pkg for me. I'm told to then use gengp4 to generate the gp4 file...this is where I run into issues. GenGP4 gives me error param dot sfo file is missing...

Does anyone here have any knowledge on how i repack this devmenu update to the base game? I'm lost now lol

Any help or advice is greatly appreciated