Neat. By a strange coincidence, I made something similar yesterday in a script to make each letter in HTML into a different font. I wanted to see if it would end up as an OCR-proof font:
https://gist.github.com/tonyb486/0e3efc9240953c86a50a019b56c...
An example: https://tmp.tonybox.net/chbgr.htm
Rasterized and OCR'd: https://tmp.tonybox.net/ocr.pdf