Query regd. rw rootfs

[Ravi Paluri (QUIC)]

Hi All,
   I'm new to OpenWRT development.
I see below text from OpenWRT documentation @ https://openwrt.org/docs/techref/preinit_mount#failsafe.

"The root file system is actually an overlay which can be consisted of a read-only SquashFS file system (mounted at /rom) and a writable JFFS2 partition (mounted under /overlay)."

As rootfs is made rw via overlay, any changes made to sensitive files for e.g. /etc/password (deleting a line etc.) will have adverse impact on security and some init scripts may not start etc.
On systemd, changes made to sensitive files via overlay (present in upper directory) won't be read at reboot but instead only lower directory will be read, so it wont harm the system.
Is this behavior the same with procd?

Thanks,
Ravi