I still think this is a solid proposal, and I want to push back on the "too advanced" argument.
Vintage Story already includes teleporters, gliders, and complex mechanical power machinery. A mechanical refrigeration compressor is less advanced than any of those. The game has clearly established that its tech level permits precision mechanical systems when built from the right materials.
The compressor doesn't need industrial CNC tolerances. Brass is in the game, it's ductile, self-lubricating, and easily worked into low-friction moving parts. Lead is in the game, it's resistant to ethanol attack, and it's trivial to cast or shape for components that contact the Aqua Vitae. Both metals are historically appropriate and already implemented.
This isn't about introducing anachronistic technology — it's about giving Aqua Vitae a meaningful late-game use beyond drinking. The closed-cycle design fits the game's engineering aesthetic: it requires active mechanical input, has clear trade-offs (heat rejection needs exposed sides), and scales with player infrastructure. It's not a magic block; it's a system that rewards building windmills, waterwheels, and gear networks you've already invested in.
The absorption refrigerator and ice cellar alternatives are fine ideas too, but they don't conflict with this. They could be earlier-tier solutions. A mechanical system fills a niche: active, controllable, scalable refrigeration for players who have already built mechanical power networks and want to put that infrastructure to new use.