Would it be possible to introduce drawing functionality? like that you can draw whatever you'd like on the block. Maybe the option to draw in 32x32 would also be nice to be able to write on blocks.

I have thought about it. While that would be cool, that definitely would not match that vanilla feel I am aiming for.

I know this is closed but thought I'd contribute a bit. I think this is an awesome idea and opens so many doors for chalk, even though I personally don't think it would be too far out of vanilla's vibe, maybe it could be a configuration option "allow free drawing" or something.

Well, it could make a good addon mod. If someone wants to contribute: sure.