I don't think the problem is on the cylinders. What are the odds of putting one cylinder longer on various tractors?
To me, it seems like the loader manufacturer has a problem on the welding jig for the loader arms, therefore causing all these problems. They might not have realize the problem though.
I agree with this, it is not the cylinders.
The cylinders can be removed from the loader frame,, and the bucket will still show the same twist.
Try it, if new cylinders are coming, you will need to remove the cylinders anyways,,,
set the bucket on a saw horse,
with the bucket supported, remove the lift cylinder, and lay it on the ground,,
The bucket, sitting on the saw horse will not "twist" the frame.
The saw horse can be under the right side, the saw horse can be under the left side,,
it will not matter,, the unlevel bucket will remain unlevel.
You can also remove one cylinder, and chain the removed cylinder in the closed position while it is on the ground.
the other cylinder will now move the loader arms through the travel range.
it does not matter which cylinder is removed, left or right, the bucket will remain unlevel.
The side that is high, will remain high,,
You can test this, and prove the cylinders are not the problem by simply removing one cylinder.