I would've like to have been paired, but I felt I was ahead of villains range. I don't think I made a mistake here, but I do have questions if this is too deep? I feel he calls with all his AAXX hands, regardless if he has a FD or not. IM 40% and he has basically one of the best hands he can have on this board vs my hand.

Im new to PLO so just wanting thoughts or if anyone plays differently . Apologies in advance if this is super standard.

And for some reason I can't find the button to put results in spoiler....

Winning Poker Network (Yatahay) - $0.05 PL Hi (6 max) - Omaha Hi - 6 players
Hand converted by PokerTracker 4

Hero (UTG): 185.4 BB
MP: 65.6 BB (VPIP: 89.86, PFR: 34.78, 3Bet Preflop: 21.43, Hands: 71)
CO: 743 BB (VPIP: 21.93, PFR: 11.40, 3Bet Preflop: 8.24, Hands: 231)
BTN: 118.2 BB (VPIP: 24.59, PFR: 14.75, 3Bet Preflop: 8.70, Hands: 61)
SB: 503.2 BB (VPIP: 40.48, PFR: 23.81, 3Bet Preflop: 11.67, Hands: 171)
BB: 151.8 BB (VPIP: 35.29, PFR: 7.84, 3Bet Preflop: 2.38, Hands: 102)

SB posts SB 0.4 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.4 BB) Hero has 9 6 5 8

Hero raises to 2.8 BB, fold, fold, fold, fold, BB raises to 8.4 BB, Hero calls 5.6 BB

Flop: (17.2 BB, 2 players) T 2 7
BB bets 16.4 BB, Hero raises to 65.6 BB, BB raises to 143.4 BB and is all-in, Hero calls 77.8 BB

Turn: (304 BB, 2 players) 4

River: (304 BB, 2 players) 9

Hero shows 9 6 5 8 (Flush, Eight High)
(Pre 40%, Flop 37%, Turn 3%)
BB shows K K Q A (Flush, Ace High)
(Pre 60%, Flop 63%, Turn 98%)
BB wins 288.8 BB

4.8 BB was deducted from the pot for the jackpot.

Well played.

I WILL GIVE THIS A SHOT.

1. You shouldn't open with this hand from UTG.
2. You shouldn't even be consider calling a 3BET with this hand it should be a muck.
3. If you are sure that he have 40% of best hand on the flop this
would mean Villain has to have 10 10 Ace Ace with the nut flush draw and your hand are
a huge dog so you need to fold to his flop bet instead of raising him.

4. Yes on this flop you do flop a full wrap where any 9,6,8,J but they have to be a non diamond.
5. Some ppls will be ambitious and start counting the diamonds in their hand as blockers for the flush draw
in this scenario. I strongly advice you from doing it because it will lead to you developing bad habits that will cost you money in the long run.
6. This is a reason why it's recommend that if you are going to play single suited hand in PLO make sure that they are nut flus draw hand.

7. THE GENERAL CONSENSUS OF EVERYONE HERE IS FOLD THIS HAND PRE FROM EARLY POSITION.

1. Meh, can't be too wrong to play this for a 2.8x BB open with 2 150BB stacks in the blinds.
2. Easy call. Folding to the 3bet would be a mistake - even if you ignore your diamonds, your equity is easy to realize IP.
3. Folding to the 3bet would be a mistake. You have 29% vs topset with the nut diamond draw and you only need 27% to call.

Anyway to answer OP's questions:
Look at your opponent's stats: 35/8/2.5%. Very doubtful you will ever be ahead of V's range on this flop. Flat the flop bet.

I agree with fold pre. but if you open, you should call the 3bet.

postflop I guess not much you can do when you flop like this. you could consider calling it down if you think there is no fold equity since you'll either improve to a strong hand or be stuck with 9high. the way it ran out I guess you would go broke anyway.

Raising flop forces a situation where you fold out the weaker parts of his range and getting called/raised by Add,T+: (dd,986+),98+:dd,T7+ which has 62% equity versus you. Calling the cbet is the way to go and you will have alot of bluffcatchers on straight/flush runouts where he might fire off and you are making sure your range isnt too weak when calling flop bets.

You should just stick to raising the nutted parts of your range.

Definately not a open preflop.