From what I understand CMF now works by installing system drivers. I don't think it is possible for a limited user account to install some drivers at all/ completely. Therefore to ensure every system can update there is a warning displayed to use admin permissions to carry out updates. The reason why the Firewall does not ask is because this update process replaces/ copies files into its working directory instead of installing drivers - therefore does not require admin permissions.
Nice explanation: makes sense.
Thanks for the enlightenment.
Regards,
Mike