Engineering your own voynich

[mja0075]

What I would be interested in is whether ChatGPT's solution was logically consistent i.e. does it work? Or is it fundamentally flawed? I haven't checked this.

It doesn't work, the mappings it gives as examples aren't used when it's "deciphiring". 
If you follow up with it and ask it to give a full algorithm or key, it will apologize and say it made a mistake.