Really cool work - I've been looking for something like this for some time and have played around with HVIF and IVG to that end.
@ikskuh since I see you here in the comments, I have one nitpick: I don't think it's fair to compare your binary format to an uncompressed SVG file since they are most often used online (and often used even offline) as gzip- or brotli-compressed resources. It would be nice to see an additional comparison between gzipped TinyVG and gzipped SVG to help even the playing field.