UCI: Making a config read-only?

[Michael Jones]

I wish to make a configuration file read-only in UCI.

I tried to do this by bind-mounting the default config for it in /rom
onto the file in /etc/config.

However, while this does prevent changes to that config from
persisting across reboots, it doesn't prevent changes from showing up
in, e.g. "uci get" or "uci show", because uci is storing the changes
in /tmp/.uci/

Is there a way to truly make a configuration read only in UCI, so that
changes are rejected, and not stored in /tmp/.uci/ ?