Big kudos to <@U0EACPP46> for making the insides m...

# minutest

[dmcg]

Big kudos to @natpryce for making the insides much cleaner and safer. We've lost some flexibility that had been gained from playing fast and loose with type-safety - I think that we may be able to put that back when we're feeling clever, but for now please let me know if anything causes any headaches and we'll try to ease the transition.