The majority of the action in Pot limit omaha (PLO) should occur post flop. Even hands that look like gold, like AAxx and KKxx, might be even money or even behind against multiple players pre flop.
The best pot limit omaha players wait till the flop, turn, and river to out play their opponents. It’s easier to put players on a hand based on their betting in previous rounds, and you’ll have a better idea of the possibilities your hand can make by the river.