My take on this is a place where we can discuss topics which could be confronting or upsetting to most members, so they would have to accept that they could be exposed to such conversations before joining that forum. The forum would still be moderated and personal attacks, people trying to 'win' a discussion by shouting others down, deliberately trying to sabotage a topic, or being generally disrespectful to others would be warned and face moderation.
The advantage of that is that the other forums can be moderated to a higher degree, providing a safe and welcoming space for those with heightened sensitivities. And in this space, we have our fair share of people with heightened sensitivities who really need forums like this. For them, it may be life and death. Also this Is a way to grow this site, while still allowing the hard subjects to be tackled.
The only problem I see is that it might attract combative people who wouldn't confine their behaviour to the restricted forum, and would require constant moderation in the other forums. It would also require moderators with very thick skins, and they couldn't get drawn in to debates and take sides. Do we have staff who could handle this? I have seen staff drawn into diversionary comments on important threads, and this can't happen in the restricted forum. If we think we can control it, I say go ahead, but it will be challenging.