I am going to sound very ungrateful at sight of anything new given the state of affairs, but I will bite. I think UI kits are as much a matter of taste as it is a technical concern and the screenshots provided does not "do it for me", not in that it is missing what I want but it has things that just won't fly for me, for example those hanging title bar controls, I could probably remove them, but it is not a good start.

That's the thing - this is neither new nor just a "UI kit". This is a 30+ years old technology (see Be OS - https://en.wikipedia.org/wiki/BeOS and Haiku OS - https://www.haiku-os.org/ ) ! It is a full-fledged integrated Desktop offering. It has its own display server and does not use Xorg or Wayland. (As for the windows title, it can cover the whole window too - it's configurable). All the extra bells and whistles that we want (and do not want) will eventually come once the product is fully developed ... right now, they are working on porting it and ironing out all the bugs.