How to remove “error: failure writing sector … to hd0” warning when booting Ubuntu 22.04.3 read-only using overlayroot on write-protected hardware?

I am trying to boot Ubuntu 22.04.3 read-only using overlayroot on write-protected hardware such as Kanguru Solutions WP-KFT3-32G flash drives.

I do following to make sure disk is read-only (meaning that not a single byte should be written to disk, ever).

Step 1: set ext4 and vfat filesystems to read-only

$ sudo sed -i 's/errors=remount-ro/errors=remount-ro,noload,ro/g' /etc/fstab$ sudo sed -i 's/umask=0077/umask=0077,ro/g' /etc/fstab

Step 2: disable fsck.repair

$ sudo sed -i 's/quiet splash/quiet splash fsck.repair=no/g' /etc/default/grub$ sudo update-grub

Step 3: set overlayroot to tmpfs

$ sudo sed -i 's/overlayroot=""/overlayroot="tmpfs"/g' /etc/overlayroot.conf

Problem is that on ThinkPad X1 Carbon Gen 6, I get “error: failure writing sector … to hd0” warning when booting and on ThinkPad X1 Carbon Gen 10, computer hangs on black screen after Grub selection (I believe both issues are related).