I've downloaded the fwupdate 0.5-2ubuntu7/fwupdate-signed 1.11.3 proposed from an XPS 9350 running BIOS 1.5.0 on Ubuntu 16.04.
I successfully upgraded to 1.6.1 via UEFI capsule and booted back into Ubuntu.
I also confirmed that there is no remaining Linux Firmware Updater \fwupx64.efi NVRAM EFI entry.
I've downloaded the fwupdate 0.5-2ubuntu7/ fwupdate- signed 1.11.3 proposed from an XPS 9350 running BIOS 1.5.0 on Ubuntu 16.04.
I successfully upgraded to 1.6.1 via UEFI capsule and booted back into Ubuntu.
I also confirmed that there is no remaining Linux Firmware Updater \fwupx64.efi NVRAM EFI entry.