"As I understand it, in classical notation, once you have applied an accidental, this is also applied to following instances of that note in a bar, until cancelled by a natural"

That's actually something that the transposition shouldn't care about. All I care about is changing the letters that you've given me. abc handles the rest.

"Boredom is for the very unfortunate persons who are severely disabled."

Boredom means you need something to do. This was something. I did it.

And don't worry, once it actually reaches v1 I'll submit it somewhere. Currently it's 0.4.3 until I'm confident that I've got all of it.