Oracle Cloud Serial Console Shell no longer works after a debi install

[greatwolf]

After a successful debi install, the Serial Console Shell stops showing output after a certain point in the bootup process. Note that the instance otherwise works fine, eg. I'm able to ssh into it, web services continue to function etc.

From searching around, the problem seems to stem from grub not outputing to serial tty during startup. This instructional blog provides a possible solution: https://pieterhollander.nl/post/oracle-free-tier-debian-install-amd64/. In particular adding/modifying /etc/default/grub with the following lines:

# /etc/default/grub
GRUB_TERMINAL_INPUT="console serial"
GRUB_TERMINAL_OUTPUT="gfxterm serial"
GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200"
GRUB_CMDLINE_LINUX_DEFAULT="splash console=tty0 console=ttyS0,115200"

then running sudo update-grub or sudo update-grub2 afterwards.

Is there anyway to modify debi.sh so this is the default behavior so Oracle's Serial Shell works properly after a debi install?

Thanks