So most people play fold or raise Vs single raises from SB. But what about multi way. So if V are all unknown what does your SB flatting range look like in these two situations if you use one:

1. UTG opens 3x, MP fold, CO calls, BTN fold.
2. UTG fold, MP opens 3x, CO fold, BTN calls.

Interested to see how people adjust here.

In theory, your SB flatting range should be even smaller in multiway pots than it should be when faced with a single open, since you need to have a hand that beats more players. You can call more often when facing a minraise and a call (better pot odds and still plenty of stack depth for a decent SPR), but vs a 3x that creates so much dead money, almost everything that's playable maximises EV by squeezing, not calling.

Examples from Snowie:
1. Only call JJ-99, squeeze QQ+, AK, KQs and all suited aces.
2. Call 99-88, squeeze TT+ and all the other hands listed above.

Feel like this makes sense if V are playing optimal but at the micros they are not. Do we not get extra implied odds in these spots or are they lost due to positional disadvantage?

Snowie 3 betting linear in both spots? I'm surprised its not polar
Is snowie folding AQo is situation 2?

It's probably a combo of those two things w/ positional disadvantage slightly weighed against doing this over the long hall. Though it should be fine if fish/whales are in and you have something middling like AJs.

It's somewhat polarized, as it squeezes A2s+, but folds AJo.
I just re-checked my old Snowie charts (I don't have the software any more), but it has AQo as a squeeze vs UTG+CO call, a fold vs MP+CO, and a squeeze vs CO+BTN, but I didn't make a chart for MP+BTN, so I'm not sure about situation 2. AQo is clearly very close to breakeven as a 3-bet, so it's not a huge mistake to always squeeze with it in SB. Calling is not good, as AQo plays pretty badly multiway as a call OOP. You can only call with the middling pairs because they flop monsters that can happily play for stacks 3-way, or they have simple check-folds. AQo flops hands that can't check-jam for value and get called by worse (except on KJT).
One additional reason for not calling in the SB is that the BB gets an even better squeezing pot, and it's not great for you if he overcalls either, as then you have to beat three players while you're in the worst position.

I agree with the above that you can flat AJs/ATs if all the villains (inc BB) are very bad. Most players at low levels haven't got a clue about how to play multiway, so you might be alright going "nut-mining" by calling instead of 3b/folding with some suited Broadways.