It's a probably limited event, why would you time limit it too?? nobody likes the acolyte system, nobody likes the day/night cycle of Cetus, why implement it here?
It's not a serious timed mode - it's no more than 10 minutes of downtime between appearances as an absolute maximum, with the next one queue up right away.
The missions are endless, so you can gracefully transition between waves without pressure.
The first thing on the team's mind when hearing about the wave structure was 'avoid toxicity in time pressure for the event'.