@maleza
So I just read this wonderful idea of yours, and something came to mind. Maybe it'll be of use to you.

https://en.wikipedia.org/wiki/Z-order_curve

Instead of "decoding" your hexadecimal representations of nibble drawings implicitly as left-to-right and downward, you could use this Z-order-curve.

This would allow you to create drawings of abitrary size (and dimension if as a rule you crop zero-nibbles) from a single hex number.

As the Wiki pages shows, you could even expand to 3D drawings (idk what that entails).

I hope I made sense.