There’s a new zigbee fan controller available from Home Depot that some community members are trying. I’m not sure if it has a wall switch, though, it might just have a handheld remote.
Otherwise if you want to go zwave, you need two devices, One for the light and one for the fan speed control. Some people use two switches side-by-side and a double gang box, some put one switch on the wall and put a micro in the fan canopy and make one of the options changeable only through a tablet or phone app. Or minimote. This gives you a full integration, really the only downside is that it’s not a single gang wall device.
Lutron does have a fan controller which has light and fan speed in a single gang device, but it’s not from the Caseta line. To get integration with SmartThings you need to also have a harmony hub in the room with the switch. And it’s a one-way integration, which means if someone makes a change at the wall switch, SmartThings won’t know about it. So not a very satisfying solution, but it does work for some people.
I’m great with two different swiches for light and fan and it’s what I have right now with GE ZWave Light and Fan dimmers but I honestly don’t like the functionality. I think it’s not intuitive to hold down the button on the top or bottom to adjust the dimmer up or down.
You’re right. Without ST knowing about the device it’s definitely not very satisfying. Maybe I’ll just put an ActionTiles panel above the dimmers and just use that.