I know of no reason that moving around the Ubuntu directory on your ESP would solve an efibootmgr failure. If the cause of this wrote for you is that your firmware has been marked read-only by the previous kernel bug in Ubuntu 17.10, this will definitely not correct that problem.
I know of no reason that moving around the Ubuntu directory on your ESP would solve an efibootmgr failure. If the cause of this wrote for you is that your firmware has been marked read-only by the previous kernel bug in Ubuntu 17.10, this will definitely not correct that problem.