Does anyone know if it’s possible to connect the Aeonlabs Z-Stick to the SmartThings network, so I don’t have to completely remove my two Multisensor 6 units and all their rules in order to update their firmware?
I’ve tried to just ask SmartThings to look for new things, but it doesn’t seem to fetch it. Is there a way to force it into SmartThigns so it can talk to my Multisensors that way?
What you can try is to create a fake device, and in the device manager manually replace the network id of the fake device with the real device. Then remove the real device. Update it, add it back to smartthings and replace the network id again. In this case, the rules stay in tact.
At least thats what worked for my Lightify Osram bulbs.
It’s technically possible to add a secondary controller like the Z stick to smartthings, but it doesn’t always work very well.
SmartThings is intended as a multi protocol platform, and for that reason it doesn’t use controller replication and a few of the other advanced Z wave features.
Fortunately, the zstick does have the option to request network updates, which does allow you to do a little more. It still gets pretty clunky.
(Note that the previous poster’s comment about virtual devices does not apply to Z wave devices. That method only works with zigbee devices like the lightbulb described because a zigbee device has its own unique ID that it tells the hub at the time of pairing. Z wave devices are given an ID by the hub. Also, the method the previous poster described doesn’t have to do with bringing in a device from a different network, as you are considering.)
@erocm1231 and a few other members have been using zsticks with their SmartThings hub as primary, hopefully they will have more to add. 
You need to put the SmartThings hub into inclusion mode and then with the Z-Stick and Zensys Tools put the Z-Stick into Learning mode. It is the little lighting bolt icon. After the Z-Stick is a secondary controller, you will have to request updates from the SmartThings hub whenever you add a device to your network from the hub (as @JDRoberts mentioned) . Looks like this: 
At this point, updating the Multi Sensor 6 is a little different depending on how it was joined to the network. If it was joined while USB powered, then you just find the node in the upgrade app provided by Aeon and click the update button. If it was joined while battery powered, you need to temporarily set the sensor to send its wake report to the Z-Stick. The code for the SmartThings device handler would be (replace nodeid with the id of your Z-Stick - in hex):
zwave.wakeUpV2.wakeUpIntervalSet(seconds: 300, nodeid:55),
You may also need to associate the sensor to the Z-Stick (I can’t remember at the moment):
zwave.associationV2.associationSet(groupingIdentifier:1, nodeId:55)
Then, when you hit the update button in the Aeon firmware update tool, the update tool will tell you that it is waiting for the sensor to wake up. Press the button on the back of the sensor and the firmware update should proceed.
Which device handler are you using for the Multi Sensor 6. If you are using mine I can guide you more regarding where to put those lines of code.
I’m thinking of finally adding my Z-stick. Any concerns now that the Classic App is discontinued?