I also had a similar idea a few years ago for a CTF challenge, coming at it from...

hyper_reality on Nov 20, 2018 | parent | context | favorite | on: Rot8000

I also had a similar idea a few years ago for a CTF challenge, coming at it from a "modern Caesar cipher" perspective: https://laurencetennant.com/unicode-shift-cipher

Also a crude "modern Bacon cipher" using Punycode characters as the B's and ASCII-range characters as the A's.