Proxy-read maps incomplete?

The current default value of proxy_read_maps is:

    proxy_read_maps = $local_recipient_maps $mydestination
        $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps
        $virtual_mailbox_domains $relay_recipient_maps $relay_domains
        $canonical_maps $sender_canonical_maps $recipient_canonical_maps
        $relocated_maps $transport_maps $mynetworks

this omits at least "smtp_generic_maps" and perhaps other tables that
could be included. Should smtp_generic_maps be added? If so, what else
is missing?

-- 
        Viktor.