If you have access to the console (local physical machine, VM on a system that can expose the console, physical box that you have console access to via IPMI or other means), can you not specify that directive to be passed through via grub's interactive menu?

Failing that you could try the “single” directive and poke other configurations once booted in that mode.

A faf to be sure, but hopefully viable options (assuming the interactive menu hasn't been disabled to save a few seconds off boot time!).

That's not correct. If you stop the boot you can add 'single' to the boot statement which will drop you in a single user shell from where you can do quite a bit of maintenance.

AWS at least provides serial console access so have the option to access it during the boot cycle.

Alternatively, you umount the drive, attach it to another machine, chroot into it, fix grub or whatever, reverse the process and boot again. It's a few steps, but can be done in a few minutes with practice.

Out of band management is common and highly recommended

Actually networking and ssh come up for a couple of seconds before containerd triggers the kernel panic so you can fix it by doing this:

while true; do ssh <servername> sudo mv /usr/bin/containerd /usr/bin/containerd.backup ; sleep 1; done

While rebooting the system

Sorry, what? You don't lose complete control of a server because it's rebooting nonstop.