Wait, what now? I have mine set to retain 3 full days of continuous.
Space management for rolling retention is also a new feature in Frigate and very basic, I don't think it has a way to do different retention policies by camera group and alarm.
Frigate already supports customizing recording retention per camera for 24/7 and event based recordings.
You can also set different retention periods based on the type of objects that were detected.
There's only been one incident where I would have liked continuous, I've tweaked events to be more than enough.