Using the first 2 hour not contactable on SC provision has eliminated all of this for me. I check my schedule when I go on SC and if there’s anything on it I show at the airport 2 hours later. You can check your schedule any time you like in that 2 hours and it’s not notification. As for GS, I’m on my way right now. If they call again there’s no obligation to answer once the assignment is made. The response time is highly variable due to circumstances outside my control like traffic.