I think Townsville Tribune is way fun, but I would more worry about SEO. One of the biggest challenges with moving off of Fandom is that the new wiki would have to compete with Fandom wikia for traffic -- and they pay Google to hit top results. If there's nothing like "Powerpuff" in the title, I'm worried it would get less traffic.
I think that making separate categories or separate tags for different kinds of canon vs fanon pages would be helpful. I know that for the Backrooms wiki (backrooms-wiki.wikidot.org) they have different categories for essays, "factual" additions to the canon, people, places, and just tales, i.e., fictional works. The new wiki could have an area dedicated to fanon information. They also have "sub-levels", so members can write additional information that is an extension of an individual page, and have it linked on the first -- that way, fanon information/interpretations of information could be linked to the main page, but it could be clearly marked as an interpretation or a fanon.
Btw I literally made an account just today after more than a year of lurking on this site just to contribute in this discussion. This topic is important to me and I want to help out if at all necessary.
