You can take a look at my ST_Anything project for examples of using microcontrollers with SmartThings & Hubitat. It might give you some ideas on how to handle the ST Groovy Device Handler side of things. You cannot really dynamically add/remove tiles from a device… however, you can add Child devices on the fly, based on what data is sent to ST. This is exactly how ST_Anything’s Parent/Child Device handlers work.