I've done a small project with Dioxus on Blitz. It is principally very close to Xilem and in fact is using some of the Xilem components. https://github.com/DioxusLabs/blitz

Yes, we are collaborating closely with Linebender on Parley (the text engine) for which we have contributed a lot of code mostly for additional layout features (like the ability to layout images and other content inline with text).

And slightly less closely on the Vello renderers for which we haven't directly contributed much code, but which we support as backends for Blitz which we have used to help with validation and testing.