Wow! That’s a lot of different subjects tangled together, as well as the fact that this topic was two years old before you responded to it and there are literally over a dozen newer threads that discuss central scene commands and various types of instant status, and I’m tired today, so I don’t want to spend too much time in this topic. So I’m just going to try to untangle a few things, and then let’s continue the discussion in one of the newer topics which is more relevant to the current generation of devices. 
I’m going to number the following points, not because of any implied sequence, but just to keep the tangled subjects separated.
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“instant status” Is just a marketing term and was never trademarked. So it can apply to many different ways of communicating between dimmer and the hub. It is not limited just to the Lutron patents – – in fact those patents don’t use the term at all.
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the Three most common ways to do “instant status” in a zwave network are: the method covered by the Lutron patents (which was implemented with the “hail” command), direct Association, and central scene commands.
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“Hail” is actually the other way around from what you’ve described. It was used by those companies that did license the Lutron patents, most notably Eaton cooper and Leviton. Most other companies initially used direct association to provide something similar, but as of 2017 most switched to using central scene commands.
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What you describe is pretty much how the Lutron patent worked: The dimmer notified the hub that there had been a change at the wall switch, and then the hub requested the current status. This was to allow it to get the current dim level, which was the trickiest part technically of the whole process.
Direct association works by having the wall device tell both the dimmer switch and the hub to do the same thing. The hub ignores that part of the request, but gets the information without violating the Lutron patent used in Hail.
Central scenes work by having the wall device tell the hub a specific code, And then the hub tells the dimmer switch what to do based on which code it received.
- There seems to be a lot of confusion about what direct association does. But it has been discussed many times in other threads in the forum so I’m not going to go over all of that again here. Here’s one thread that discusses how a lifeline Association group in zwave plus works:
Note that per the standard, all zwave plus devices must support lifeline group association.
Also:
also have owned a GE 14294 Dimmer and it supports three separate types of COMMAND_CLASS_ASSOCIATION (Lifeline, Load (Tap?), and Double Tap).
That’s three separate association groups, not types.
https://products.z-wavealliance.org/products/2105/assoc?noFilename=True
- That said, the basic purpose of direct association was to allow one device, such as a motion sensor, to send a “basic” (that has a very specific meaning in a Z wave context) Command to another Z wave devices in the same room (like a light switch) without having to tell the hub about it. That’s all it’s for. By associating the two devices together, you are giving the trigger device permission to send one specific type of command directly to the target device without going through the hub first. It’s not very useful in a smartthings set up as then you can’t put any additional logic On the command, you can only use it with other zwave devices, And you can only use it with devices which are physically nearby.
So if you set up the motion sensor to tell the light switch to come on, that will always happen – – even if it’s the middle of the day. Other methods, including central scene, would allow You to only have the motion sensor event trigger the light coming on between sunset and midnight, or only in certain modes, or to also include lights on the other side of the house.
- You can read more about how association works in the public specification
http://zwavepublic.com/specifications
- “Decora” Is a trademark of the Leviton company and refers to what are now commonly called “rocker” switches.
However The first generation of Z wave switches made by Leviton were not rockers. And so not called “Decora.” Instead, they were a momentary switch where you always pressed at the bottom of the switch whether you were turning it on or off. Some people like this, some people hated it, but that’s just the way it was. Then in 2017 Leviton came out with a new line of “Decora Smart” switches, including a zwave plus Model, which did look just like their dumb Decora switches ( Press the rocker at the top for on, press the rocker at the bottom for off.)
Old style (not Decora)
New (2017) style (Decora Smart)
Back in the original line there was a set of budget switches, of the kind where you pressed at the bottom whether you wanted to turn it on or off, Which did not license the Lutron patent and so were less expensive. But that line has now been discontinued
- You can find further current discussion of all this in the Homeseer switch threads.