Title says all

I don't think so. I dont even think K'un L'un exists in the MCU

I doubt it effects Hell, because everybody there is already dead, and doesn't require consumption of the resources Thanos is apparently trying to preserve. It's confirmed not to effect the Quantum Realm, which is why Lang survives and is unaware of the snap. That also makes sense because the Quantum Realm doesn't necessarily operate in accordance to the same physical properties that the Infinity Stones control. I think K'un L'un already got murdered in the MCU, but I geuss we'll never know that.

It has killed half of everything that is inside the MCU Universe regardless of whether or not its in a separate dimension because it would still come under reality which one of the stones affect.

And most dimensions here are physical 3D instead of the dimensions we read in physics so there's not much very different between all the dimensions physics wise.

K'un L'un dosen't exist in the MCU and the snap did not effect the quantom realm as Scott suvives

K'un L'un does exist in the MCU. It was in the Netflix shows and the Netflix shows do exist in the MCU, they just don't operate on the same level as the Avengers. I'd like to know the source of the confirmation of the Quantum Realm not being affected, I've been searching for it for a while.

Yes. Kun'Lun though probably doesn't exist because Netflix part of Marvel is iffy and MCU doesn't really claim it as being canon or part of thr actual universe and I'm happy with that. At best it's alternate dimension.