I don't know if there's much point in working with Ybos code for this because ACS 4.0, which is due out early next month, will have group-scoped bboards. In fact, I believe that alpha2 is available today to play with.
Having said that, let me add two disclaimers. First, I have no first-hand familiarity with either the Ybos module or the ACS 4.0 bboard, so this is all going on what I've read. Second, if you're committed to using OpenACS 3.x for the foreseeable future, then the Ybos module may make more sense. I doubt the 4.0 bboard will port to 3.x.