A Cipher Thought Experiment

[nablator]

I'm not sure I understand all the details, since some of the combinations behave weirdly sometimes, could be some extra mechanic or could be typos, this is not really important as long as it's possible to reconstruct the message.

I see. There is a clever use of a binary state, either "copy mode" or "simple letter substitution mode", that resets to "copy mode" at each word start and after "/", and switches to "simple letter substitution mode" after any bigram substitution. Bigram substitutions are done first, left to right, otherwise there could be some priority issues.

Also some typos, for example:
MT/ORNO/K (thoric) should be LT/ORNO/K (doric)