Also I have not familiarised myself enough with any of the rainbowfic writers' canons to feel confident in writing in those settings. I made intros and storylists for my own settings hoping to make them more accessible, but also I have written relatively little in all of them, making the canons pretty open, but then there is also the awkwardness of asking.

I don't know if it's been done before, but we could maybe have a roll call post, or self promo post, for people who want to offer their worlds to be collaged. In replies, could add descriptions to entice people, and advice on how to write in that setting, and how much they would really need to read/absorb to do it with confidence. It lowers the bar significantly.