Note, @erocm1231 mentioned elsewhere that he no longer has one of these devices and is not working on this device handler anymore.
I actually wrote a patch to his handler to do things the new way, and then decided it was better to integrate into the zwave-multi-button handler, for two reasons. Firstly, it’s common code across several devices so it is more likely to be kept updated with core changes, and there are no fundamental differences between this and some of the devices supported there (except the number of buttons). Secondly, the different namespace was causing subtle problems which are avoided by just using the smartthings namespace.