No
We already have three ways to workshop questions in use, in increasing order of complexity/escalation.
- Comments on the question. This works in 90% of cases where the OP bothers to engage at all.
- Site chat. This works for the really confused and newbies.
- Opening meta questions when it's a real sticky one. This works for more advanced users seeking to ask a tricky question. The specific-question tag contains examples.
We don't need a fourth. Firstly, because it only helps if the user is sophisticated enough to find the sandbox (so the "but they're new but don't have rep to come into chat" - the only real gap in the above 3 - isn't a high percentage play). And secondly, because it's not our job to make every question workable. If someone has a question so unworkable that 1-3 above don't work - they need to stop and not ask it until they've engaged more with the site to focus their thoughts. Or get some rest, or whatever. We do get questions asked that are incoherent and the OP eventually admits they were "sleep deprived" or "drunk" or "didn't have time to write properly"... Those are THEIR problems not OUR problem. If they don't have enough rep to get into chat, maybe they should participate in the site a little before asking. Remember, we optimize for pearls, not sand. So while I understand wanting to help people with their questions, we believe that meeting them more than halfway teaches people to be help vampires and doesn't make them a good participant on this site.
In fact, this question was opened - with good intent to help, I understand - but spurred by a question from a user who has asked a long, long series of incoherent questions on this site, all closed and/or deleted, under 6 different usernames because they also aren't sophisticated enough to log in. That's exactly the kind of questions we don't need to do even more work to engage with - that user's unteachable.
I understand Worldbuilding has one, but Worldbuilding is quite an experiment that has just about nothing to do with the SO format. It might as well just be a forum with up/downvotes like reddit (though with a Be Nice rule, so better...). We adhere to all the usual Good Subjective/Bad Subjective and other standard SO quality guidelines here so really don't have anything in common with what's effectively a brainstormy format. If someone wants to make "RPG Brainstorm Stack Exchange" feel free, I'll be happy to not visit it, since I already belong to a bunch of forums.