opends- help with custom object class

we have 2.2.0 of opends running on RedHat 2.6.21 and we're trying to setup a structure that will suit our needs. One of the things we'd like to do is create our own custom object classes based off some of the existing ones you get out of the box. The opends documentation covers this here (sorry, it won't let me post the link but search for HowToExtendTheLDAPSchema):

Is it better to update this file directly or to create separate ldif files and load them into ldap?

thanks

It seems like you can modify ldap with ldif files, even if none are now present: Linux LDAP Configuration - Segetech Open Source Rendezvous