I know a bit about the IRMB.
So we had these Randomness Wars with the IRMB, which was when a large part of the SAMB decided that they would go over to IRMB and try to spread fluffeh. Of course, the IRMBers did not take this well, (think of it like Europeans trying to colonize the world), and they peacefully told us to stop. We didn't, and eventually the conflict got so bad that it got several people banned, and others left of their own will.
There was also an IRMBer called Emerald, who ended her life around this time. I don't know if it was before or after the Randomness Wars, but at any rate, the IRMB was in a pretty bad shape after going through these ordeals. People left until the place eventually deteriorated and became like a ghost town, and then the mods decided that an empty message board had no use and turned it to internet dust.
I'm fairly certain if the SAMBers had properly respected the wishes of IRMBers, the IRMB would still be alive.
I also remember that one year where the WoF forumers and SAMBERS were basically leaping at each other's throats. (2016?) I posted on both places so I just kinda avoided it, but everyone on one side was accusing the other side of trying to take over, and vice versa. SAMBers thought WoFmbers were homophobic and aggressive, and WoFmbers thought that SAMBers were stuck-up and controlling. Everyone eventually calmed down, and then the newer generations came in and were so accepting of people no matter what mb they were from I was like ??? How come we couldn't be like that?
Anyways, good luck making the book! The forums are such an interesting case to study, and the events that occurred here can apply to events that have occurred irl.