In this context, “dumb switches“ are ones which do not have a radio inside. For that reason, they will have to be connected to the master switch with physical traveler wires, they don’t have any other way of communicating.
They also will not show up as devices in the smartthings app.
Just to be clear (it gets super confusing as our ticketing queue often shows lol) both auxiliary and dumb/existing switches do not have a radio inside of them, so we try to make a distinction between using the word auxiliary and dumb/existing, but we’re also open to whatever the industry norm is and if we’re misusing the terms, we will definitely change. I’ve just seen aux and dumb mixed up a lot so it’s confusing. Example from this morning:
Auxiliary = GE/Honeywell, HomeSeer (special add-on switch)
Dumb/Existing = $2 toggle switch that was already in your house (example: https://www.lowes.com/pd/Legrand-radiant-Single-Pole-3-Way-Gray-Compatible-with-LED-Rocker-Light-Switch/1000844164)
From a network engineering/device design standpoint, “dumb” means “no radio.” Those devices will not be assigned network IDs and will not show up in the app.
From a home-improvement industry/building code standpoint, “auxiliary“ means “not the master“ whether it is a dumb switch or a smart switch. These might also be called an “accessory“ or “secondary” switch and the master might also be called the “primary.“ but this terminology only applies to light switches: otherwise an auxiliary switch means something else. (Yeah, it’s confusing. 
) and some manufacturers have their own terms: GE calls them an “add on“ switch.
I know some people who always say “an auxiliary switch in a three-way“ to make it very clear what they are talking about.
Anyway, so typically an auxiliary switch in a three-way could be either smart or dumb. And if it’s a dumb switch it could be specially designed to work with a smart master or it could just be any standard light switch.
Lutron calls a regular light switch a “mechanical” switch.
Leviton calls a regular light switch a “standard” switch and calls the auxiliary in a three way a “remote.”
so as a device manufacturer you can pretty much call it whatever you want, just be prepared to explain your own terminology frequently.
I started my smart home automation 4-5 years ago. At which time, I updated the garage door opener, front door lock, thermostat, smoke detector, and about half of my home wall switches (2nd floor and basement). I was using the Simon XTI panel with Guardian Protection through alarm.com. All of the existing contact switches and motion are old school radio bases, not z-wave. I did end up doing 1 - 4 way (on the stairs), and 2 - 3-way switches (for a room) around the house
For better or worse, life got busy and end up stop working on its, up until recent COVID 
While looking through home-automation again, I was looking through Homeseer, Home assistant, and few others. In short, SmartThing 3.0 seems to hit most of what I needed to do, but may still go take a Home Assistant at a later time. As one concern I have with ST is that it is cloud base, so if my Internet would go down, I would assume I am screw I am technical but still green to the Z-wave protocol. One thing that stood out for me so far with ST is the ease of excluding and adding in a node (in most cases), and the recent tweak I find for the association. I tried that in the past with Aeotec Stick and it was a total pain.
I am in the process of replacing all of my radio-based sensors first (motion and door contacts). Probably going with ST contacts (even though it is zeebee) and EcoLink Motion. But one huge investment left for me are the remaining wall switches. Through out the years, few of my Evolve switches (master) went bad on me (15 %) , thank god I have some spare. But I do not have enough spare to finish the rest of the house. However, I do have over a dozen Evolve accessory switch (LTM-5) which I would like to use. I am not sure if it is right or wrong, probably more subjective than objective, I would probably using the same wiring method I been using where I will replace all of the switches to Z-wave, both the master and all of the accessory in a multi-way configuration. I just need to ensure that whatever brand I am going with will indeed
It looks like those evolve aux switches control the primary over zwave, without the traveler wires correct?
I have used models similar to these before and they work good.
Just be aware that you will have to do some manual work to setup the zwave association.
You will have to get the zwave id of the primary switch you want to control.
Then use zwave tweaker to setup the associations.
Yes, it creates virtual three ways between the auxiliary switch and the primary.
The evolve does control the primary over zwave, but it does need power. This is why I tie the traveler and AC in together on both the master and acc so there is always power going into both switches at all time
Can all three manufacturers able to do what I am suggesting and work with other 3rd party master switches? Inovelli seem to have more bell and whistle, but need know if it would work. However, I did read about Inovelli seem to have a little more lag time between pressing on the button to when the light actually turn on. Thoughts anyone?
No.
GE add on switches don’t have a Z Wave radio and will only work with their own master switches.
Zooz doesn’t make auxiliary switches, only master switches. They recommend using a standard mechanical switch as the auxiliary in a three-way. Technically you could use one of their master switches as the auxiliary in a virtual three-way, but I’m not sure that would work with your wiring set up.
Inovelli doesn’t make auxiliary switches either. They recommend using the add-on switches from GE or Homeseer, both of which require a physical traveler wire.
I don’t really understand what you’re doing with your wiring, it doesn’t sound standard and you wouldn’t be able to use it with any smart switch that required the use of the traveler wire. But I would leave further discussion to the electricians know much more about this sort of thing than I do. 
(I was a network engineer. I know device specifications quite well, but when it comes to the wiring for any given installation, I’ll leave that up to the experts.)
In order to get a set up similar to what you had with the evolve switches you need to find a company which makes an auxiliary switch for a three-way which does have a Z wave radio in it so you can use it in a virtual three-way. That would include Gocontrol, Eaton Cooper, or perhaps an Inovelli or Zooz master switch set up for scene control instead of load control. But most of those would require a neutral for the auxiliary switch.
One other option that does not require a neutral would be the Qubino module. That does not require a neutral although it might require a bypass if the load is too low. And that could get to be an expensive solution, it wouldn’t be my first choice.
So putting everything all together, the switch which would be most like the one that you are used to is the gocontrol accessory switch. But I would have an electrician review your wiring plans before finalizing a selection.
Let me ask you this way, for GE, can I use master for all the mutli-way switches. And just use the Z-wave association to turn on and off the light
The GE is not designed for that option. (Again, GE doesn’t make those devices, they have just licensed their brand to Jasco, and they are intended as budget devices. people like them because of their name, but the engineering has historically not been as good as the other brands we’ve been discussing.)
The inovelli and the Zooz do each have an option that lets you bypass load control for one of their masters. Although intended for control of smart bulbs, it can also work to make the switch part of a virtual three-way.
And the GoControl is specifically designed for exactly the use case you described: to be the accessory switch in a virtual three-way.
@dwchan69
Partially, were these strictly switches or do you need dimming? Dimming is harder to get good behavior.
Zwave plus switches all have some capability to control other zwave devices using zwave association.
Using these dimmers and zwave association good behavior is hit or miss.
And SmartThings does not make it easy to setup the associations
Many do, but The only zwave plus requirement In the protocol is for association group one, the lifeline group, which would not be used to control other switches. Otherwise it’s up to the manufacturer.
So you still need to check the conformance statement at the official Zwave product site or read the manual to see if the device supports association for other association groups.
The Z wave Tweaker does work with the new V3 app, so although it’s not an official feature, it’s not that hard.
If you’re familiar with the IDE …
Good point, it’s definitely not as easy as some of the other platforms like vera or Homeseer, but, again, it’s not that hard. Basically cut and paste the code into your account.
FAQ: An Overview of Using Custom Code in SmartThings (SmartThings Classic)
I played around on HomeSeer a little, and used the aeotec stick as a stand alone with my old system, the z-wave tweak on ST by far is the easiest for me so far
The latest custom device handlers for Zooz switches have built-in association fields for easier programming if anyone is looking for that type of functionality (so you no longer need to to turn to the tweaker tool).
Can you elaborate? Are you saying I can do the associate right from the physical switch? Or somehow ZooZ branded switch has more option on the ST 3 APP out of the gate?
If you install a dedicated custom device handler, for example as described here for the ZEN27 model, you’ll be able to input the node ID for an associated device straight from the device’s advanced settings. It’s a little more intuitive to use than the Z-Wave tweaker (otherwise a great tool!) and less work to do the programming over all.
