The Elk is a good solid security system, but I would be surprised if anyone can create something for SmartThings which is comparable to the integration with vera or homeseer.
Although SmartThings is a certified Z wave controller, it is designed as a multiprotocol cloud –-based platform. It doesn’t handle multiple controllers well, either as a secondary or primary. In fact, you can’t even add a second SmartThings hub to the same “location,” obviously a very different architecture than Vera, where adding a second Vera hub is the recommended solution for a number of use cases.
SmartThings is certified at the basic level, but does not include a number of advanced control and management command sets, such as controller shift and controller replicate. It also provides no mapping tools at all.
In fact, the company goes so far as to specifically advise against ever adding it as a secondary:
https://support.smartthings.com/hc/en-us/articles/204392790-Z-Wave-general-info
SmartThings strongly discourages adding the Hub to another Z-Wave network. We cannot offer support for disconnected Z-Wave devices or the inability to add devices through the Hub as a result of including the Hub into another Z-Wave network.
On top of all of that, ALL custom code, even device type handlers, written for SmartThings has to run in the cloud. That adds an additional point of vulnerability as well as possible lag.
And finally, SmartThings can and does push out firmware updates that can be neither refused nor delayed, which can take the hub off-line from anywhere from a few minutes to several hours and sometimes require resetting devices afterwards. I just mention that because elk is often deployed in areas where there is limited Internet connection or where maintenance access may not be available 24/7.
So… You may find someone who will offer to write this for you. I just want to be sure you understand that you are not likely to get something comparable to what you could get with a vera or homeseer integration, both of which are primarily Z wave platforms, not cloud-based, which integrate easily with multiple zwave controllers.
FWIW