I've heard that the patrol zone rewards* is pointless since you can get plenty of dubs from other sources.
My suggestions is to add victory marks to the reward pool so perhaps 70k damage is 4,000 dubs and 1 Victory mark, 200k damage is 6,000 dubs and 2 Victory marks, and 500k is 9,999 dubs and 3 Victory marks.
It would make the Patrol zone more lucrative for one, and would have people in the zone for longer. Especially those who don't get Victory marks from ports.
*edited for clarity