Good catch. Seem to be the issue (including NFSv4 not affected). Are you able to build an image with the patches?
With your remount finding and the mount-storage.sh feature here you can try to create this file in your boot= mount point to work around the issue:
Bash: mount-storage.sh
# Warning: if using "overlay" the target directory is not created
# Use default command to mount storage
mount_part "$disk" "/storage" "rw,noatime"
# force rw to work around kernel issue, see https://lore.kernel.org/lkml/[email protected]/T/
mount -o remount,rw /storage