Well, there is SmoothLife (e.g. https://www.arxiv-vanity.com/papers/1111.1567/#S4 https://www.arxiv-vanity.com/papers/1111.1567/#S4) where the time step is also

Well, there is SmoothLife (e.g. https://www.arxiv-vanity.com/papers/1111.1567/#S4 https://www.arxiv-vanity.com/papers/1111.1567/#S4) where the time step is also made continuous. I suppose you could extend this so that this isn't some uniform value across the entire space, but instead a value that is constantly recomputed based on neighbourhood density.