But the point of the 4K seems to be to reproduce the intended, original CRT look on an LCD. The only other good way to get that right now is a real N64 and a $1000 retrotink 4k, isn’t it?

Even then, you don't start getting CRT motion on a flat panel display until that flat panel is updating at at least 1000hz, so it'll be a while before we have emulated tube shaders that are like, convincing. Even the RT4K shaders look great but you wouldn't mistake them for real in motion.