It's a nice idea, but I think separating them off would just make it far less likely that they would ever gather a team and actually get moving as fewer people would see them. If you don't want to post an idea in the Forge, then you can do so in the General forum. I can remember at least one example of a one-line mod idea that was posted here which snowballed.

And I'm not too worried about the Forge getting crowded (so long as they're relevant and not threads that should be somewhere else). The mod threads that have activity on them pop back to the head of the list pretty regularly, and those which are moribund slide away to subsequent pages.