Today's first session produced more of the short-term frustrations of running badly against EV, but the session itself provides a concise number of hand examples to illustrate this, as the damage was essentially done within 3 hands out of the 400 played. Rather than being a "woe is me" kind of moan about how unlucky I am there are a couple of worthwhile talking points within it, with one hand in particular being quite an eye-opener.
To begin with, here's the summary of the session in question (Eulalia is the PLO10 Zoom table, and Thyestes is the PLO25 one):

So overall, I ran $57.19 below EV, playing 50BB buy-ins ($5 and $12.50) at the two limits.
These two hands account for just over $10 each of the difference:
PokerStars - $0.25 PL Hi FAST (6 max) - Omaha Hi - 6 players
Hand converted by Holdem Manager 3
BTN: $90.94 (363.8 bb)
SB: $69.94 (279.8 bb)
Hero (BB): $12.50 (50 bb)
UTG: $25.00 (100 bb)
MP: $22.84 (91.4 bb)
CO: $35.45 (141.8 bb)
SB posts $0.10, Hero posts BB $0.25
Pre Flop: (pot: $0.35) Hero has 4♦: 5♥: A♦: A♠:
UTG raises to $0.85, 2 folds, BTN calls $0.85, fold, Hero raises to $3.50, UTG calls $2.65, BTN calls $2.65
Flop: ($10.60, 3 players) 3♦: 2♣: 7♥:
Hero bets $7.61, fold, BTN raises to $15.22, Hero calls $1.39 and is all-in
Turn: ($28.60, 2 players) 7♦:
River: ($28.60, 2 players) 3♥:
Results: $28.60 pot ($1.22 rake)
Final Board: 3♦: 2♣: 7♥: 7♦: 3♥:
Hero shows 4♦: 5♥: A♦: A♠:: (Two Pair, Aces and Sevens)
(Pre 60%, Flop 37%, Turn 0%)
BTN shows 7♣: 7♠: T♣: 9♥:: (Four of a Kind, Sevens)
(Pre 40%, Flop 63%, Turn 100%)
BTN wins $27.38
Fairly straightforward stuff. I've got draws to the wheel on the flop, so have some additional equity to backup the Aces for the OOP shove. Sod's Law that oppo has hit his set, which improves to quads.
PokerStars - $0.10 PL Hi FAST (6 max) - Omaha Hi - 6 players
Hand converted by Holdem Manager 3
BTN: $7.14 (71.4 bb)
SB: $37.77 (377.7 bb)
Hero (BB): $12.61 (126.1 bb)
UTG: $6.83 (68.3 bb)
MP: $10.34 (103.4 bb)
CO: $10.15 (101.5 bb)
SB posts $0.05, Hero posts BB $0.10
Pre Flop: (pot: $0.15) Hero has 8♦: 7♦: 5♦: 9♣:
UTG raises to $0.35, MP calls $0.35, 2 folds, SB calls $0.30, Hero calls $0.25
Flop: ($1.40, 4 players) 5♣: 6♦: 9♦:
SB checks, Hero checks, UTG bets $1.34, 2 folds, Hero raises to $5.36, UTG raises to $6.48 and is all-in, Hero calls $1.12
Turn: ($14.36, 2 players) 7♣:
River: ($14.36, 2 players) T♣:
Results: $14.36 pot ($0.61 rake)
Final Board: 5♣: 6♦: 9♦: 7♣: T♣:
Hero shows 8♦: 7♦: 5♦: 9♣:: (Straight, Ten High)
(Pre 47%, Flop 76%, Turn 68%)
UTG shows 2♣: A♦: 4♣: J♦:: (Flush, Ten High)
(Pre 53%, Flop 24%, Turn 33%)
UTG wins $13.75
This one was somewhat uglier on the run out as I successfully dodge the nut-flush draw he planned to hit, but didn't avoid his backdoor flush draw getting there.
The hand that did the most EV damage ($31.46) was one played with close to a full 100BB stack at PLO25, after I'd built up from the original 50BB starting stack:
PokerStars - $0.25 PL Hi FAST (6 max) - Omaha Hi - 6 players
Hand converted by Holdem Manager 3
BTN: $30.69 (122.8 bb)
SB: $24.11 (96.4 bb)
BB: $11.40 (45.6 bb)
UTG: $28.26 (113 bb)
MP: $26.30 (105.2 bb)
Hero (CO): $23.57 (94.3 bb)
SB posts $0.10, BB posts $0.25
Pre Flop: (pot: $0.35) Hero has K♠: A♥: A♠: 3♣:
fold, MP raises to $0.50, Hero raises to $1.85, fold, SB raises to $3.20, fold, MP calls $2.70, Hero raises to $13.05, SB calls $9.85, fold
Flop: ($29.55, 2 players) 5♥: 2♠: Q♣:
SB checks, Hero bets $10.52 and is all-in, SB calls $10.52
Turn: ($50.59, 2 players) K♦:
River: ($50.59, 2 players) T♠:
Results: $50.59 pot ($2.00 rake)
Final Board: 5♥: 2♠: Q♣: K♦: T♠:
SB shows 8♥: 9♥: T♦: 2♦:: (Two Pair, Tens and Twos)
(Pre 45%, Flop 35%, Turn 38%)
Hero shows K♠: A♥: A♠: 3♣:: (One Pair, Aces)
(Pre 55%, Flop 65%, Turn 63%)
SB wins $48.59
The flop here is pretty dry and I have a gutshot into the wheel and a backdoor nut-flush draw, so the flop shove is absolutely standard.
Having stopped shaking my head at what the SB had 4-bet then called a 5-bet with, I was really intrigued on reviewing the hand to see that he still ends up with circa 35% equity on the flop via pairing the deuce, so the final call is justified by pot odds at that point. It's one of those PLO hands where you have to look twice to see if you read the figures correctly as, when the hands are flipped over, you are simply sat there thinking "WTF?".
Looking back, it's a really good illustrative hand for those coming into PLO from NLHE to demonstrate the general point about equities running much closer. It still annoys the hell out of me to have lost it, but I can justify his flop play, at the very least.
The other general observation I wanted to make comes from looking at my EV graph over the last 3 days play, from the perspective of the bankroll challenge I'm attempting.

I'm almost $300 down vs EV over the 4,500 hands played since Monday. That's nothing in terms of sample size, and nothing out of the ordinary in terms of an EV swing playing PLO. However, its also 1.5 times my starting bankroll for this challenge, being played at the same limits I started with (albeit there's a higher proportion of PLO25 in the mix compared to the starting play). Consequently, it's a really good demonstration of how high the risk of ruin is from the challenge, and how essential it is to have the backup of the rakeback earnings to make it remotely feasible.