Help required for DH for ZConnect Garage Door Module

Welcome to the forums! While I don’t have the exact answer you’re looking for, you could check into the developer docs for creating smart apps. However, most z-wave devices will not need a special device handler for most functions.

I would remove the device from ST, z-wave exclude.
Then When you + add a device in the ST app, does only one relay show as a new device to add?

Also, if you’re looking for the custom settings, you can set them withz-wave tweaker community app, then switch back to a generic z-wave device handler. The settings should remain after switching back. You could do that without deleting the device you have and repairing it etc. Just install z-wave tweaker custom app, publish etc then change the device type in the IDE to z wave tweaker.