Option to disallow manually adding/removing Smart Group members

I have created a number of Smart Groups which are based on queries of my custom fields. I would like to prevent the ability to manually add or remove members of specific smart groups because this conflicts with the fields I use to define group membership. Could we add a checkbox in each group's settings that disables manual adding/removing?

In any place where the option to add members to a group, the groups should be not displayed or grayed/disabled out to prevent selection. eg on the Group tab when viewing a contact I would like those specified groups to not appear on the "Add to a group" dropdown list. Other places I recall are the "Edit" page for an individual or the "Add Contacts to a group" feature after doing a search. There may be others.