That’s all cool stuff and it’s possible to do so, with the libraries we do have in the core. As the examples show but somebody would have to implement it.
I think several community members can implement the wikitext elements that are possible already, as I showed at HowTo Compare the Content of a Shadow Tiddler With the Content of an Overwritten Shadow … The merge options would need some js-code, but to make the differences visible is wikitext only.
The core devs have to deal with about 1.1k open issues, where probably half of them are still valid and about 160 open pull requests with probably about 30% are still thinkable.
So until we can clone several devs none of that will happen in the near future if the community does not step up more and actually start to try to contribute to the core using GitHub