How do i revert adding a permenant boot arg from initramfs?
Solution 1:
You can boot into recovery mode from the Grub menu and this will bypass the kernel arguments on GRUB_CMDLINE_LINUX_DEFAULT. From recovery mode, you will be able to edit your /etc/default/grub file to remove the arguments. Also, don't forget to run sudo update-grub to apply the changes after you are finished editing the file.
To explain: arguments listed after GRUB_CMDLINE_LINUX_DEFAULT are not passed on when using recovery mode. See here for more information.