After 6 months of developing XEP-198 for Smack it's nearly finished and support for Stream Management will be included in the next release: Smack 4.1 (although disabled per default). I'm not aware of anyone persuing XEP-198 support for Openfire *and* releasing it open source. I've heard that there is a closed-source XEP-198 patch for Openfire. But I can't comment on the code quality, stability or usefulnes of that patch.
If no one is willing to contribute XEP-198 support (for free), then you either have to pay a developer to implement it, or use a XMPP server that does support XEP-198.