I just want to do a drive by comment to compliment you and the rest of the Lit team on Lit. I love how using a TS compiler is optional, I'm impressed by how fast and pragmatic lit-html is, and how easy it is to understand how it can be fast (vs, say, React's virtual DOM). Lit has a Redis-like quality of simplicity to it, like good Italian food and very much unlike eg React or Vue. I could study the architecture for an hour and feel like I completely grokked how it worked and why.
I can't say I completely love the OO aspect of it (notably the amount of boilerplate it requires to define props), and personally I think Lit would've been more powerful if it were optional for LitElements to be Web Components (having a million nested shadow DOMs by default is, well.. let's say it makes some common pragmatisms like global CSS overrides needlessly hard. also a single global namespace for tag names gets messy fast, and so on). But given the goals you set yourself, Lit is absolutely amazing. Small, fast, easy. Hats off!