The in wall modules can communicate to smart things, so they can tell smart things that the switch was double tapped, so you could have that then trigger another event like the heating – – but that part would only work while smartthings is operational. That’s always going to be true.
Any device which controls the current load to the fitting, including the in wall modules, can continue to perform that function even if smart things is down. So the wall switch is physically connected to the in wall module via the wiring to the fitting, and that part will still work for dimming.
As far as indicator lights those will always require the SmartThings cloud at this time. It’s just the way SmartThings is architected.
Have you considered using a wall-mounted tablet for things like the indicators? That’s a very popular approach with smartthings. It only works with the smart things cloud, but it does give you a lot of options.
Smart tiles is a very popular third-party dashboard app that works with smartthings. It can run in pretty much any browser. So you just select whatever tablet you like. You can customize the colors, tile size, and exactly which devices show on each tablet. And you can tap the tiles just like you can in the smart things things list. So you can turn things on and off or change light color, etc. from the tablet – – as long as the SmartThings cloud is available.
www.smarttiles.click
So you just you could get just dimmer switches for the lights control and add a dashboard for everything else.
There’s a thread in the forum where people discuss various customization options, including hardware:
