Honestly, I've been around the Heroimm process enough that I'm pretty sure most of the details to the areas aren't likely to see the light of day. CF has a lot of uniqueness that I think everyone would be happy to not see copied elsewhere.

I think in general, if you wanted to sorta "headstart" an area, I would just come up with a layout, plan for mobs and items, and descriptions for everything. Keep in mind, even if you write something up, it might get shot down after you Heroimm. But if they like the theory behind it, the plan of what goes where, and the descriptions (room , exits, mob descs, items short and long descs, etc) is a lot of the work. The rest is just the actual "putting" of things in their places.

Of course, I could also be entirely wrong in what I said, but that was the roughest part for me :P