No, it's not a complete integration. To do something like that requires a lot of work and will probably not even be possible with a commercial system. The integration is for the user system and being able to comment on articles and such. If you want you can use UBB.threads in an iframe inside Mambo and you will have something similar to a complete integration.
I don't know of an exporter to get UBB.threads info to Simpleboard unfortunately.