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This one didn't. It was literally just a featureless button, engineered with intelligence it couldn't possibly need except as a means of locking out third-party hardware.

Even the "dumb" buttons are on a common serial bus with Security+.

I agree that it is annoying in a "It's just a momentary switch! How hard can it be!" sort of way, but it be that way anyhow.

It's Security+ or Security+ 2.0, it is literally obfuscated serial traffic over two wires. It is DRM. You can't just get any random button to open/close the garage.

No, it's DRM. On older models, control over auxiliary functions worked by the buttons connecting capacitors of different capacitances across the two wires (the door control itself was still a direct short). This works fine; DRM is indeed the only reason newer models changed it.