There was a self-hosted CLJS project for Node.js which is now abandoned. It was called lumo. It came with a custom image of Node.js with lumo built-in for better startup times since the JS bundle of self-hosted CLJS is quite large resulting in not so great startup out of the box. Nbb is just a library that you can use with any Node.js version. That said, it might be worth revisiting the self-hosted CLJS approach at some point.

But the slow-starting, big-bundle default one still works right? For someone developing an electron app maybe it would be a useful option.