Do we have evidence there is actually a demand for this? Any lurkers want to pop in and say they would like this?

Not sure if I qualify as a lurker, but, well... this is a dojo. If a little kid walks in here and asks a stupid question, rhetorical and logical ass-kicking will commence. The virtues of rationality number twelve, and mercy is not among them. It's all terribly serious.

I have a theory about fiction, which I would like to test. People take fiction less seriously, because they aren't personally involved, but they can still learn from it (which explains the fallscy of generalization from fictional evidence). If it was possible for newcomers to adopt an explicitly fictional persona, and roleplay as budding rationalists within a fictional setting, I predict that would get more new people engaged. There is considerable precedent for success of online roleplay communities, and no reason I am aware of to believe that establishing a fictional setting with the explicit goal of rationally exploring the fantastical elements of that setting would be less successful.