In addition to what´s been said: when in mission mode and a failsafe event occurs the AQ will always complete the mission first. The wait time in stage 1 (PH) gives you a chance to regain control by approaching the position of the craft.
I´ve only forced failsafe a few times but let it perform the RTH & land instead of trying to regain control while in stage 2.
Be very careful when testing these features!