As said on http://www.xmpp.org/extensions/xep-0163.html#publish : "A PEP service SHOULD also support the "publish-options" feature defined in XEP-0060" but OpenFire doesn't. So we can't change PEP node configuration settings.

Pubsub publishing options are defined on http://www.xmpp.org/extensions/xep-0060.html#publisher-publish-options