So the literally imperceptible immeasurable amount that the canisters expand and contract have that much of an impact on the atmosphere of the entire earth as to cause the stack to push down on one and let up on the other until they balance out? How does the atmosphere know which one to push down on? How does the atmosphere choose?
What's worse is even that explanation wouldn't make sense. Because if you had a container with a gas that you heated, it would expand and get lighter. The opposite of what's being claimed here, that it expands and gets heavier.
Maybe atmosphere stacks are sentient. 
Understand the stacking system and why pressures increase and decrease within it and why displacement of it is relevant.....then you may start to understand.
All I see is brush off without even bothering....which is fine but it doesn't help you.
I've read pages and pages and pages of your posts, it's not me, it's you. 
You still can't explain how gas moving between two containers on a sea-saw would cause it to even out. The containers don't expand or contract, so how does the 'air stack' know what's in each of them?
You have yet to explain this. Maybe you need to understand your own theory first.
I know my own theory. It's been explained. You simply do not know it but think you do.
Your belief that nothing contracts and expands with containers is your issue. You know they do but you just can't comprehend the pressures that are changing to make this happen.
I could go from the very basic up to the steel containers like those on the see saw but I just know it'll be lost....as simple as it is.
I'll give a it a go and trust me I'm not expecting anything back of acceptance.
Let's go right back down to the basic containers and how atmosphere acts.
We will start off with a balloon.
We fill the balloon with a gas and the balloon expands due to the gas being compressed inside and pushing against the external atmosphere but only by the amount it's already taken from it in order to inflate/expand that balloon.
The skin of that balloon is not stretched to the point of exploding due to the atmosphere inside of it being compressed much more into a smaller space with balloon walls resisting the internal compression/crush aided by the external atmospheric crush.
Take away that external crush and the balloon is already breached because it expands with little resistance.
However, this would only be happening in atmosphere where there is much less resistance...which is higher up....so we'll leave this bit as it's just there for clarity if we need to get to it.
Ok, so how do we hold more gas in a container?
Let's use a rubber water bottle, the one you use for bed.
Fill that with gas and you find it can hold more compressed gas than the balloon...but what it hold is only taken from the atmosphere/Earth.
The skin once again will stretch. It will expand due to internal compression but it will hold much more atmosphere due to it's higher skin resistance.
We could go on with clear to see expansion of rubbers and such.
However, let's more rigid plastic.
Pressurise it and you will notic it bulge slightly.
Same with thinner metals.
However, if you use more rigid resistance like thicker steel and even thicker plastic, you can massively pressurise it and even condense it into liquid without visually seeing any expansion....but it's there.
The difference is, we are talking super compression within and normal atmospheric 14/15 pounds per square inch of pressure externally, which is a massive aid in stopping the expansion of the gases/liquid, just as the smaller internal make up of the container is for holding that pressure.
You see, the container is being kept from expanding by the much denser make up and that much denser make up is already displacing it's own dense structure of atmosphere, as is, with it's material.
However, it still expands and contracts, depending on circumstances....but you can't see it, yet you can certainly hearit at times.
I know, I know.....but it can't expand enough to cater for change.
It does. It does this with the aid of atmosphere. It has to do this in equal terms, just like the balloon....etc....all within the atmospheric stack any object finds itself in.