Interesting. Runs app on the server, does final rendering of the UI's scene graph on the client (within the browser). It's not clear from skim reading if the client side rendering is implemented with the DOM or a canvas element. I've always thought it'd be hysterical to use canvas. The whole browser just to hoist a client side frame buffer. X-Windows reinvented. FWIW, JavaFX is so close to The Correct Answer™. Defini…
The canvas is a powerful tool, especially if you do a lot of graphical work. Rendering the entire UI yourself, gives you complete freedom of layout management. Plus, you avoid any DOM manipulation, directly or through a myriad of JavaScript frameworks. Remember: there is no silver bullet. Example: https://www.isochart.com
Implementing something that looks like and behaves like a web page in a canvas on a web page is a "of course it's possible, but there must be a better solution" moment.
If you then have to pay for the amount of RAM of your central layout/rendering process, it would make it hysterical, as in "maybe we could pay less for RAM if we figured out how to offload layout and rendering to the client".
There's probably a niche for this still, because Java isn't inherently bad (pun intended), and if you run out of time but keep getting requirements, this thing could make your existing app be more like a web page, but if you're starting from scratch, why wouldn't you not use this?