I love how you've really explored the depth of the gold milling mechanic! I'm also really impressed by the rewind feature, that works so well for the most part. I think there's only a couple things I want to note, and they might not even be real issues:
- I'm not sure if the rewind feature is intended to allow this, but if I stepped on a conveyor that took me to a pit, I could rewind to a point on the conveyor belt and stand there, and walk off of it in another direction. I was able to use this to bypass at least one puzzle. Disregard this if that's literally just the intended solution.
- I reached a point shortly after getting the ability to split gold into wires where I don't think I had the resources to solve the puzzle, or I was just missing something, but I'm not able to return to a previous room. Again, if that just skill issues, disregard.
Job well done!