It's unlikely since the smallest possible jpg 10x10 jpg is just under 300 bytes. You might be able to squeeze out a few dozen bytes if you tried multiple browser supported formats (e.g. jpg, webp, png, gif) and pick the smallest one since they might be better at encoding blurhash's gradient effect.
I'm sorry, I wasn't clear about what I meant. The idea was to convert the hash to JPEG once it reached the client, so that the browser's native JPEG support could be used to display and cache the image.
