It depends on what you are willing to live with.
My Chamberlain myQ-connected garage is currently “semi-connected” to SmartThings. I cannot use ST to control it in any fashion; however, I can use myQ to report events to ST, and to drive events in ST.
Given that the myQ app does allow me to control the garage on its own, this works for me. I have no scenarios under which I would want my garage to automatically open or close just based on timers or ST events. What I have it do, via Tasker/AutoNotification, is to pop notifications on an android control tablet. Those notifications are recognized for their content, and tell ST whether the garage is open or closed.
ST can then report such status, and can act on it (for example, turning on particular indoor lights if the garage opens and it is after sundown).
Not optimal, but functional.