OP, this functionality was something I had hoped for with the new myChevrolet app update. It might've converted me from the RemoteLink app to the myChevrolet app. Sadly, this was not the case. In another thread about broken charge complete notifications, I thought the update was related to the Bolt becoming available soon. New features like scheduled precondition and navigate and show nearest charging station. Still hoping for a future update...
I've had varying times and success remoting starting. Sometimes it doesn't go through until the 2nd attempt. 2/3 of the time, I get it to finish within several seconds. 1/3 of the time, I'm counting more than 20 Mississippies (sp??) and my Volt still hasn't started. FYI, I have a security camera pointed at my Volt so I can see when it starts the precondition. There's yet another time variance: the time from precondition start (visually confirmed) to precondition acknowledged on the phone app. I've waited up to 5 seconds for the app to show the car is preconditioning after I see the car lights. This is all via WIFI as my cellular reception is not great at home.
I think you're thinking of Tasker? That one can I believe simulate user interaction to mimic your start of the app and entering of the PIN code, but I recall you need to be root to enable tapping in the PIN code.