This will be the tough one… I am curious how you plan on running this locally on the hub? Is SmartLighting capable of handling a hobbled together Garage Door Control set of devices? If not, even if the devices are able to run locally, the SmartApp will still be cloud-based.
I originally wrote ST_Anything in order to monitor and control my two garage doors. It uses an Arduino + W5100 Ethernet Shield (or you can use an ESP8266/WiFi), along with some magnetic contact sensors, and a pair of relays. It has been rock solid for many years, except for the typical SmartThings issues. I have since moved everything over to my Hubitat hub, where all code runs locally. Now it is incredibly reliable and quick.