You can do very complex stuff without any need for React like approach. I literally said I've written a very sophisticated framework that was exceptionally snappy - that's what should be used for that 1% (not my framework, but the approach). Even better, I could introduce it very gradually and strategically on different SSR pages and then (if I wanted to) I could turn the whole app into an SPA - all without needing to "render" anything with JavaScript, VDOM or other such nonsense.

Is this framework public? I think the same way as you and developed my own framework with/out the things you mentioned and would like to compare my approach with yours. Biggest difference is that I use lit-html for templating, which is quite efficient.