Oh indeed, there’s no question that the OS controller is a good deal. It has more features (single power source, shift registers for unlimited extendability), and requires relatively little in terms of install and setup. My question is mostly academic (I have no intention of changing things around at this point anyway). I do think that the relay works with 24VAC, the output is rated to AC250V and since all it’s doing is closing the circuit, smaller voltages shouldn’t be a problem (correct me if I’m wrong here).
One problem is that it seems to require wiring up some resisters and transistors to get it to interface with the RPi. What are you using to control your garage door?