New role for the access to the .index directory

Some IDEs assume they can download Nexus index files without providing credentials for authentication (for instance
Netbeans 6.8) or they ask after every restart for the credentials again (as Eclipse 3.5.1 with M2Eclipse plugin).

I wondered if it is a good idea to provide a new role like "Nexus Index Access" per repository, so I could configure
an anonymous read access to the ".index" directory and the files therein for the "Guest" user?