Comment 2 for bug 1890672

That set check_signatures=no does not work seems correct, you don't want to be able to circumvent secure boot just by editing
grub.cfg

Given that you vastly modified your boot configuration, I don't think this is actionable. I'd suggest you remove that package and maybe reinstall in case it does not fully get rid of it. Not only does it break your boot, it also makes it less secure by replacing trusted binaries with binaries you can sign just by gaining root access, completely circumventing the idea of secure boot preventing rootkits etc.