Not necessarily! You could defend the palace for the majority of the event, and then throw in your weight to assist in sealing the rift at the end, or you could work to try and understand how to close the rift in the beginning, and assist in defending the Palace throughout to save lives. Hopping in and out of the rift, too, is a disorienting experience, because it takes far less time than you think it would -- you could go through multiple dreamscapes in the span of 30 actual minutes, though it feels like multiple hours. How you divide the time is totally up to you, but playing the middle of the road will be taken into consideration on how Akvos fares at the end. :)