Allow read-only access for visitors with no IP - security considerations

We have a couple of EE sites where the setting under Throttling > Deny Access if No IP Address is Present is set to “yes”.

Unfortunately this may be causing some legitimate visitors to be denied access to the site (they are in a large organisation with NATs involved in their network) so we are considering changing this setting to “no” if this would allow these folks access.

Has anyone else encountered this issue (visitors attempting to access a public EE website from a NATs firewalled network being denied access)?