A rather radical approach to non-derailing Y's, especially used in a loop configuration, is not to use a switch machine at all. Instead, use a simple spring with your Ross switch! I do this on my layout and never had a derailment no matter which way the train is going. Here is an example of a springs in a push configuration
When a train enters the bottom of the Y, it will always go either to the right or left depending on how you permanently position the spring. Say it first goes left. When the train comes around the loop and enters the right side of the Y, it will not derail because the spring will be loose enough to let the wheels pass to the bottom of the Y. I can provide you videos to show how well this works.