When things were more fractured here we used to write ourselves notes in books, and occasionally there would be conversations back and forth that way. Mostly in that sense it was things like, "If Y calls about X project this is what we told them." "There's a doctor's appt. scheduled at such." Just basic things, not exactly conversations, just enough to pass information along. Every once in a while notes like that are now left in notepad on the computer.
Generally the journals we have are used for sorting things out between people, memories, revelations that will be helpful overall, but commentary comes from people outside the body, friends, relatives.
I think if that were to occur here it would stay on journal and out of communities, others don't need to be privy to internal debate, because sometimes it can get pretty heated and snippy, as issues are smoothed through, but I can see where it might be helpful, if nothing else just to make sure things are remembered. That's the main problem that's had. "I know we had a huge discussion about X issue last night, but everything's mushy and hazy now..."