The build 289.0 is available as beta version in the Download Links post in the "Support Forums / Product Owner's Lounge / Fusion 2.5" forum (or on Steam if you registered to the beta tests).
It's a beta, be careful and if possible make backup copies of your MFA files.
In case of problem you can reinstall any other version (no need to uninstall first, just reinstall the patch of the build you want to reinstall).
If any problem with this version, please post it in the bug box, don't post it in this forum otherwise the developers won't see it, thanks!
PS: the CF 2.5 patch updates all the installed exporters, you do not need to reinstall them.