GA Failover Options

This is so that the Application ( LTM VS) is preferred out of a DC and the other one is on Standby. Now if there is a Failure on the first VS, the alternate VS will take over and start servicng traffic.

What I am after is a way to avoid the failback. This is to make sure that the second VS remains up until we failover manually.

Just wondering if there is a way to do this apart from using Manual Resume. Manual Resume will require GTM/LTM Admins to bring this up but i would prefer that this is controlled at the application layer.