When in any app or websites, you should be able to triple tap to wake the task switching function which will enable you to navigate to other active apps or websites by scrolling left to right or right to left etc......
I had an idea, which could make it would. Samsung use Game Booster/Game Plugins when playing games. If your idea was implemented, it could also be added as a setting within game booster/plugins as something that can be disabled automatically during gaming.