The mental visualization experience in these puzzles is super fun. They should use these puzzles in schools! I'm dedicated to solving them all without using pen or paper. Reminds me very much of the process of searching the permutation space for optimal solutions in SpaceChem.
It also gave me the itch to make an automation/factory game based on your ruleset, lol... I'll let you know if that ever comes to anything.
24 was harder to do mentally, but also ended up being my favorite so far! Very neat once you figure out the constraints.
When I was at the height of my SpaceChem obsession, I would actually dream about it and even woke up in the middle of a night with a valid solution once! I suspect that game built a whole new brain region...
