Yeah: stick with your Items, Things and other configuration files 
Despite writing this tutorial, and a few others, using the UI, I found tinkering too slow with all the clicking around and page refreshing that was required. And once I’d worked out how to configure the Semantic Model and Metadata in the configuration files (to adjust and configure default UI widgets) I haven’t looked back…
You shouldn’t have to redo anything unless:
- You were using v1 bindings
- Your rules used specific date/time functions