This is an open

There's not an easy answer to "how loose are we opening" if this is in our range, because it depends on how much we value connectedness. This hand doesn't do well at all in hot/cold equity, but it's clear that a perfectly connected hand has a lot of value if stacks are reasonably deep.

What if we had 30bbs?

With 30bb easy fold

Tom could you elaborate why this is a clear open? Phil folded this hand in tough lineups quite often in his videos. I personally don't know if the IO are worse the open, it should depend a lot on the players behind, how often we play MW, get 3bet etc.
As a standard it feels really close and I might be biased but a fold from UTG and close from MP1

It's close, it depends on the lineup. With a fish at the table I'd open this, without a fish I'd fold.

My UTG opening range is generally all the big hands you would expect (AA, KK, AKQx etc) and then when it comes to smaller rundowns I open them if they are double suited or perfectly connected, eg 4567ss open and 4678ss fold.

I don't for a second think it is a perfect strategy but it is a simple way to keep some hands in your range that give you board coverage on low flops.

This single suited version seems on the loose side to me.

Preflop play is not that clear cut in PLO. Main focus should be on playability, and we want some board coverage for metagame /deception reasons. Never hitting low boards with our UTG range makes us attackable against observant opponents as we either have to simply x/fold or cbbet small or x/call a small bet etc.

Biggest downside is that if ppl 3bet a lot IP , we have trouble calling OOP.

Honestly I think it's kind of silly to generalize from Phil saying it's a fold in tough lineups. I agree with him, but that wasn't the question. How about - this is an open at least 75% of the time at mid stakes.

I have no problem calling a 3-bet OOP with this hand and 100BB+ effective. I've done math on this but it's too long and I'm tired so I guess take my word for it or don't (yay argument from (semi-) authority), but I'm confident it's profitable to call given that you've raised and that money is sunk cost.

If you knew you were getting 3-bet 100% by MP/CO/BN and the three-bettor were competent then it'd be an open-fold. But that's a contrived scenario. I don't know at which percent 3-bet probability it becomes a fold. That would be an interesting question to analyze (in the general case or with samples from multiple hand types too, actually).