I am less pessimistic than @csstup about zwave secondary controllers. But they do work as he describes.
Their initial functionality was simple: provide low latency control of a locally distinct group of Z wave lighting devices and sensors. For example, an outbuilding or an entertainment room. They were designed in the days before everybody had a smartphone and wanted real time app updates, and they worked fine for that purpose. Particularly for motion sensor controlled lighting, or for some kinds of security sensors. Vera used them successfully for years. They also work fine when you have a distinct sub system, like swimming pool controls.
But it’s not intended to stitch together two different platforms, like Leviton and smartthings, and it’s not very good at keeping an app up-to-date.
So I think it’s old technology that was fine for its time, and still has some uses, but if you try to go beyond those, you’re likely to be disappointed.
Also smartthings just never implemented the secondary zwave architecture well, whether it was a primary with an added secondary, or a secondary for another primary.
All of which is to say, I think there are still times when it might make sense to add a secondary Z wave system to smartthings, particularly, for example, for something like a swimming pool control system, but otherwise… Yeah, it’s just not going to work great.
For Leviton devices, speaking just for myself, I feel like it now makes more sense to add the Leviton end devices to a smartthings hub and run everything from there. There are several pieces missing from the official smartthings features, but the community has stepped up and provided custombuilt utilities to fill most of the gaps, including for association and several of the scene controllers. So everything works a lot better now than it did back in 2013 when this thread was first started.
Was there a specific use case where you felt you needed to maintain the Leviton controller or is it just a matter of it being too much work to rebuild everything on the smartthings hub?