[Aachen]

There's tons of combinations that take forever and nothing ends up happening. That's how I got around to the comment thread (clean+satan is why I'm here): I'm waiting for the latest combination to time out

[araes]

Similar. Snowmobile Farm and Sandbox Farm both appear to timeout with no response.

However, that said, the idea itself is a neat idea, and could quite easily be turned into game ideas somewhere.

[beacon294]

They seem to be asynchronous, e.g. you can actually combine several pairs at the same time.