After getting several replies, the missing link for my application is the display. These are high end condos, $1m plus units. Renters pay a lot of money to rent. We need to protect the unit from getting damage from sea salt, however we to avoid upsetting the renters. So it is very important to have either a smart thermostat with the message displaying on the thermostat why the A/C disabled, or a display next to the thermostat, displaying on the thermostat why the A/C disabled.
This is what happens in the rental business. (And it happens often)
The guys, (most of the time) are partying on the balcony enjoying life (which is great), its easier just to leave the balcony wide open so they can go in and out the condo, the door stays open for hours, maybe all day. With controls, we would disable the A/C, what happens next, the condo gets extremely hot and quick during the summer. And when that happens, the wife gets hot, (see the issue?) when the wife is sweating and the guys or drunk on the balcony, that is a mess up issue. Then the wife is calling the front desk complaining the A/C is not working.
With a display next the thermostat, the wife will quickly fuss at the guys to close the door. That's the goal.
The display needs to be wall mounted, near the thermostat, needs to be professional in appearance to match the condo, needs to be reliable (very important), needs to function independent from the wifi. I would like the solution to have wifi for remote monitoring "only", but not required but would be very useful to notify us if a local zigbee device fails. Etc
After getting feedback, the missing device is the display itself. I started researching displays that support zigbee and zwave.
My thought now is to consider display controller (that supports zigbee), using a zigbee door sensor to communicate directly to the display controller, which could provide the disabling function using to a zigbee relay to kill the 24vac to the A/C unit, That way anything all control communication would be using zigbee, all local. If the hubistat can communicate to display controller, then I can use the wifi for monitor only,