TLDR: The button presses on the ZEN30 are a mess, but triggering rules based on changes to the switch state do appear to work as intended.
I know this doesn't solve all the problems that people are having, but I have been able to successfully implement a ZEN30 workaround for my purposes. I have the dimmer portion hooked up to a load and operating basically in the default configuration. For the relay button, it's not hooked up to load, and set to "smart bulb" mode. Creating rules that trigger on the relay button press doesn't work for all the reasons documented in this thread. But even in smart bulb mode, the relay (or HE) does continue to track the virtual off and on state of the switch.
So I was able to create rules in RM and SAR that trigger on change in state of the relay switch rather than the button presses. In RM, that means setting the trigger to "turns *changed*". If you're using SAR to toggle a smart bulb (or similar), you set the trigger to "Switch turned on or off" and then also make sure to flip the "Also toggle when turned off" setting.
Again, this worked for me both with a simple bulb toggle in SAR, and a complex rule triggered by pressing the relay button in RM. Hopefully it's helpful to others.
