As far as triggering echo routines from a virtual switch, that’s easy. You just have to use a DTH which creates a virtual sensor that also has the capability switch. That way when you turn the switch on from SmartThings, the sensor registers as opened. When you turn the switch off, the sensor registers as closed. And so you can have your echo routine react to those state changes
See the community FAQ for the exact steps and the code for that DTH:
You just have to use a DTH which creates a virtual sensor that also has the capability switch. That way when you turn the switch on from SmartThings, the sensor registers as opened. When you turn the switch off, the sensor registers as closed. And so you can have your echo routine react to those state changes