Ok, so the 45633 should work as a button controller, based on the conformance statement.
So the answer to this topic (which is a FAQ) should be:
“The discontinued 45600 uses a zwave command class not currently supported by ST. If you’re willing to spend more, the newer 45633 has a similar form factor and should work like the Aeon minimote as a HelloHome Action controller, although you may need to customize the button controller device type to account for the number of buttons.”
Does anyone actually have one in use? And if it does work, why isn’t ST selling it?