Position is so important in PLO, even more so than NHL (of course not to say position isn't important in NHL) for several reasons.
- PLO being a capped betting game (meaning you can't just shove live NHL) means that by being in position you can close the betting by just calling, thus better controlling the size of a pot can actually become. Unlike NHL, even if you call in position say on the turn, you can still be facing an overpot sized bet or all-in. This is not the case in PLO, and this can really be a benefit to getting to showdown with more marginal hands.
- PLO has a lot more information available to you due to the extra two cards in your hand. The nature of the game also means that board texture in terms of straights, flushes, full-house combos, etc are more likely. It's often a more draw heavy game than NHL in some regards. By being in position you get the most amount of information by being able to see what your opponents do to help better make your decisions. It's much harder out of position in PLO to make the correct decisions, less information and greater uncertainty.
- PLO is a game of betting potential nuts making hands hard in earlier streets, and less of a game about bluffing by the river, of course people still bluff though. By being in position with say a made hand, like when you flopped a set on a very draw heavy flop. You can keep it more controlled by being in position, and potentially increase your chances of winning with a made hand that can often, while being the technical best hand on the flop, be an underdog to win the hand against good draws. It's harder to call out of position with a weaker two pair or set hand against pot pot from earlier positions.
Basically to sum up information, in any form like blockers, missed draws, betting, etc,etc is so important in PLO. Likewise as is the ability to control the size of the pot. Position gives you the ability to get more information and control the game effectively. It allows you to potentially get value from weaker hands that can't stand up to too much pressure on earlier streets when facing multiple pot bets.