TiddlyWiki does not have a dedicated development team, in the sense of a group of people paid to work on it full time.
Our core development “team” is a loose collective of the regular committers on GitHub, but I still think of us as a team.
My own work on TiddlyWiki is supported by my consultancy work. Nowadays all the projects that I work on involve TiddlyWiki, and so I do work with TiddlyWiki full-time, but I don’t work on TiddlyWiki full-time.
There’s some important context to that discussion. @Flibbles is in an unusual position of needing to maintain plugins that depend on the TiddlyWiki core without being a participant in the community. That’s a tough nut to solve because our development model is participatory: one finds out what is going on by following the action and getting involved.
That’s not to say that there aren’t improvements that we could make. In general, I prefer to explore ideas that have already proven successful in other open source communities. I don’t think it is our job to invent new ways to manage open source projects.
As you know, there is already a documentation wiki written by and for developens at https://tiddlywiki.com/dev, but you are suggesting going further and transplanting new feature discussions to a hosted TiddlyWiki. Those discussions currently happen on GitHub and here on Talk. I do not think we are yet at the point where TiddlyWiki can offer a comparable user experience.
It’s also worth noting that the development discussions happen on GitHub largely because there are special features there that make it simple to refer to code and issues.